15 june 2023

I didn't plan to observe last night.  This is marine layer season and frequently it would move in just as darkness falls around 10pm.  But it was still clear as others were going to bed so I decided to give it a try and uncovered the 6-inch.  There were some shreds of fog early but they dissipated, and while transparency was not great, seeing steadily improved.  I had been tired from a lot of house remodeling, but I decided to continue observing well past midnight, finally calling it quits after 1am.  Many objects observed, it was quite a good night.

STF1909 AB: 152; 300x: 44 Boo.  Strongly notched elongation, slight magnitude difference, unfortunately seeing not supporting higher magnification.  This pair is <0.5" now and starting to rapidly widen from periastron, so it will be much easier to split in the coming few years.  SOC grade 2 orbit, 214.7-year period, no Gaia parallax data.

15h 03m 47.30s +47° 39' 14.6" P.A. 141.70 sep 0.2 mag 5.20,6.10 Sp F7V+K4V dist. 12.51 pc (40.81 l.y.)

STF1934 AB: 152; 125x: Near equal, well separated.  -59% PRO, it is not binary.

15h 17m 22.50s +43° 47' 36.9" P.A. 13.00 sep 9.8 mag 9.46,9.63 Sp G5 dist. 114.29 pc (372.81 l.y.)

STF1961 AB: 152; 125x: Faint pair, wide, near equal.  -97% PRO, it is not binary.

15h 34m 35.33s +43° 31' 28.6" P.A. 20.00 sep 28.6 mag 10.07,10.17 Sp K2

STF1946 AB: 152; 125x: Very fine, 1 Dm, well separated, B can be just seen with direct vision.  31% PRO, 1,186 AU WS, 1.5+1.0 Msol, it might be binary and needs an orbit.

15h 27m 09.01s +39° 29' 35.5" P.A. 344.00 sep 7.5 mag 9.34,10.87 Sp F5 dist. 227.79 pc (743.05 l.y.)

STF1916 AB: 152; 125x: Fine pair, well separated, noticeable magnitude difference.  -71% PRO, it is not binary.

15h 09m 54.15s +38° 58' 33.0" P.A. 332.00 sep 9.8 mag 8.40,10.60 Sp F7V dist. 58.79 pc (191.77 l.y.)

STF1921 AB: 152; 125x: Wide, near equal, white.  0% PRO, 5,375 AU WS, 1.8+1.7 Msol, and the RVD 0.1 is less than the EV 1.1, it is possibly binary and needs an orbit tried.

15h 12m 00.00s +38° 40' 12.4" P.A. 283.00 sep 30.3 mag 8.56,8.74 Sp A2 dist. 141.64 pc (462.03 l.y.)

STF1947 AB: 152; 125x: Fine near equal pair, nice near split. -6% PRO, it is not likely binary.

15h 28m 09.87s +38° 21' 38.1" P.A. 26.00 sep 6.8 mag 9.98,10.39 Sp K0 dist. 109.41 pc (356.9 l.y.)

STF1938 Ba-Bb: 152; 300x: Exquisitely fine unequal BC split with 125x but better viewed 200x & 300x.  It is also just hairline split with the 60mm at 90x.  SOC grade 2 orbit, 256.5-year period, presently to the north and will stay there for the next couple of decades.  55% PRO, 85 AU WS, 1.2+1.0, it is binary.

15h 24m 30.89s +37° 20' 52.5" P.A. 1.70 sep 2.2 mag 7.09,7.63 Sp G0V dist. 36.06 pc (117.63 l.y.)

STF1965 AB: 152; 125x: 1 Dm, well split, light yellow stars.  Also split with the 60mm at 40x.  81% PRO, 987 AU WS, 3.8+3.0 Msol, it is likely binary and needs an orbit.

15h 39m 22.68s +36° 38' 09.0" P.A. 306.00 sep 6.3 mag 4.96,5.91 Sp B7V+B9V dist. 145.14 pc (473.45 l.y.)

STF1973 AB: 152; 125x: Unequal, very wide.  42% PRO, 2,491 AU WS, 1.6+1.2 Msol, and the RVD 1.1 is less than the ES 1.4, it is likely binary and needs an orbit.

15h 46m 24.50s +36° 26' 45.6" P.A. 321.00 sep 30.6 mag 7.60,8.79 Sp F5 dist. 80.19 pc (261.58 l.y.)

STF1964 CD: 152; 300x: beautiful pair, resolved with 125x but better seen with 300x.  60% PRO, 174 AU WS, 1.6+1.3, it is likely binary and needs an orbit.

15h 38m 14.14s +36° 14' 49.7" P.A. 19.90 sep 1.5 mag 8.06,9.02 Sp F5 dist. 27.59 pc (90 l.y.)

STF1983 AB: 152; 125x: Faint wide pair, B needs averted vision to see, then can hold direct.  -97% PRO, it is not binary.

15h 51m 57.93s +35° 27' 39.0" P.A. 64.00 sep 14.1 mag 10.19,11.74 Sp K2

STF1984 AB: 152; 125x: White and >1 Dm, nicely split B.  Also seen with the 60mm at 90x.  -17% PRO, but only 723 AU WS, 2.1+1.3 Msol, RVD 1.6 vs EV 2.9, so it might be binary and should be checked.

15h 51m 10.09s +52° 54' 25.2" P.A. 279.00 sep 6.4 mag 6.89,8.94 Sp A1V dist. 127.06 pc (414.47 l.y.)

STF1982 AB: 152; 125x: Near equal, faint, well split.  78% PRO, 1,090 AU WS, 1.5+1.4 Msol, RVD 0.2 vs EV 2.2, so it is likely binary and needs an orbit.

15h 49m 51.25s +42° 47' 19.6" P.A. 299.00 sep 4.8 mag 9.95,10.12 Sp F8 dist. 270.27 pc (881.62 l.y.)

STF1991 AB: 152; 200x: Faint 1 Dm pair, closely split, better seen with medium power due to their faintness. -14% PRO, only 627 AU WS, 1.6+1.3 Msol, might be some chance of binary, try an orbit.

15h 57m 26.92s +41° 39' 42.9" P.A. 195.00 sep 3.0 mag 9.45,10.41 Sp F5 dist. 178.89 pc (583.54 l.y.)

STF1962 AB: 152; 125x: Slightly unequal bright white stars, wide.  Looks better, cleaner, with the 60mm, 40x.  No Gaia parallax data on the primary.

15h 38m 40.08s -08° 47' 29.4" P.A. 189.00 sep 11.7 mag 6.44,6.49 Sp F8V+F8V dist. 26.62 pc (86.83 l.y.)

STF1925 AB: 152; 125x: 1 Dm, well split.  16% PRO, 236 AU WS, 0.7+1.0 Msol, and the RVD 1.2 is less than 3.2 EV, it is likely binary and needs an orbit.

15h 16m 53.01s -08° 17' 08.1" P.A. 17.00 sep 6.3 mag 8.14,9.85 Sp G5 dist. 37.64 pc (122.78 l.y.)

STF1914 AB: 152; 125x: Very wide, 1 Dm.  Also seen in the 60mm 40x. 99% PRO, 4,369 AU WS, 1.7+1.2 Msol, it is probably binary and needs an orbit.

15h 11m 44.63s -05° 28' 57.5" P.A. 334.00 sep 30.8 mag 8.33,9.59 Sp B9III+G0 dist. 166.67 pc (543.68 l.y.)

STF1899 AB: 152; 125x: Wide, 2 Dm, white.  85% PRO, 2,743 AU WS, 2.2+1.0 Msol, but the RVD 3.8 exceeds the EV 1.4, it is not binary.

15h 01m 35.34s -03° 09' 50.5" P.A. 67.00 sep 28.6 mag 6.69,10.15 Sp K2IV+K0V dist. 109.29 pc (356.5 l.y.)

STF1939 AB: 152; 125x: Unequal pair, wide, white.  -67% PRO, it is not binary.

15h 27m 30.27s -10° 57' 45.1" P.A. 130.00 sep 9.7 mag 8.22,9.32 Sp G0 dist. 106.27 pc (346.65 l.y.)

STF1966 AB: 152; 125x: Unequal wide pair, seen with 60mm 40x too.  -4% PRO, 2,496 AU WS, 1.2+1.2 Msol, RVD 0.1 vs ES 1.3.  There is a small chance it's binary and an orbit should be tried.

15h 41m 59.98s -11° 08' 27.5" P.A. 52.00 sep 23.1 mag 9.26,9.40 Sp F7V+F6V dist. 49.16 pc (160.36 l.y.)

STF1999 AB: 152; 125x: Well split unequal stars, with a wide trailing fainter star and a double star pair, near equal wide, in the far field.  38% PRO, 329 AU WS, 1.0+0.8 Msol, and the RVD 0.4 is less than the EV 3.1, it is binary and needs an orbit.

16h 04m 25.96s -11° 26' 57.6" P.A. 98.00 sep 11.9 mag 7.43,7.99 Sp G8V+K0V dist. 25.26 pc (82.4 l.y.)

STF1998 AB: 152; 300x: Xi Sco.  Hairline split, near equal with seeing, light yellow stars. No Gaia data for the secondary.  SOC grade 1 orbit, 45.9-year period, it is apastron to the NE currently, will close to 0.35" east by 2040.

16h 04m 22.13s -11° 22' 23.2" P.A. 13.00 sep 1.1 mag 4.84,4.86 Sp F5IV+F5IV

STF2019 AB-C: 152; 125x: Wide 2 Dm pair.  No Gaia parallax data for the primary.

16h 14m 16.53s -10° 24' 52.0" P.A. 153.00 sep 22.3 mag 7.38,9.84 Sp F7V dist. 78.99 pc (257.67 l.y.)

STF2050 AB: 152; 125x: 1 Dm, well separated.  -39% PRO, it is not binary.

16h 30m 50.02s -13° 07' 58.5" P.A. 218.00 sep 5.7 mag 8.27,9.72 Sp A0IV/V

STF2012 AB: 152; 125x: Wide, faint B needed averted vision to detect, then can hold direct.  -80% PRO, it is not binary.

16h 09m 59.90s -08° 15' 05.7" P.A. 213.00 sep 24.3 mag 8.79,11.74 Sp F5 dist. 76.63 pc (249.97 l.y.)

STF2018 AB: 152; 125x: 1 Dm, wide, white.  37% PRO, 4,910 AU WS, 1.8+1.3 Msol, it might be binary and needs an orbit.

16h 13m 46.32s -07° 38' 44.5" P.A. 355.00 sep 19.6 mag 9.29,11.00 Sp A0 dist. 3333.33 pc (10873.32 l.y.)

BU948 AB: 152; 300x: The BU pair emerges with seeing within the first diffraction ring as a hazy point. SOC grade 4 orbit, 300-year period.  No Gaia data for the secondary.  If it is binary, it will close to <0.3" to the north by 2043.

16h 05m 44.53s -06° 17' 28.1" P.A. 73.50 sep 0.6 mag 6.46,9.01 Sp F3V dist. 87.34 pc (284.9 l.y.)

STF2005 AC: 152; 125x: Wide pair, B faint but can hold direct.  -85% PRO, it is not binary.  

16h 05m 44.53s -06° 17' 28.1" P.A. 233.00 sep 28.6 mag 6.46,11.31 Sp F3V dist. 87.34 pc (284.9 l.y.)

STF2119 AB: 152; 125x: Close clean split, near equal white stars.  -16% PRO, it is not likely binary.

17h 06m 29.45s -13° 56' 05.5" P.A. 185.00 sep 2.4 mag 8.21,8.31 Sp F6V dist. 107.76 pc (351.51 l.y.)

STF2048 AB: 152; 125x: White stars, 2 Dm, well split.  65% PRO, 295 AU WS, 1.6+0.8 Msol, but the RVD 6.0 exceeds the EV 3.8, it is not likely binary.

16h 28m 48.99s -08° 07' 43.2" P.A. 297.00 sep 5.6 mag 6.58,9.74 Sp F4V dist. 50.94 pc (166.17 l.y.)

STF2132 AB: 152; 300x: Beautifully close split, near equal.  81% PRO, 353 AU WS, 1.8+1.5 Msol, it is likely binary and needs an orbit. 

17h 12m 45.07s -04° 03' 10.9" P.A. 114.00 sep 1.9 mag 8.89,9.66 Sp F2

STF2122 AB: 152; 125x: White A and wide, faint, 2 Dm B. -30% PRO, it is not binary.

17h 06m 52.94s -01° 39' 22.0" P.A. 279.00 sep 20.3 mag 6.38,9.73 Sp A8V+G5V dist. 90.5 pc (295.21 l.y.)

STF2123 AB: 152; 125x: Faint, wide, near equal.  57% PRO, 815 AU WS, 0.7+0.7, RVD 0.7 is less than the EV 1.8.  It is likely binary and needs an orbit.

17h 06m 57.50s +06° 48' 03.0" P.A. 216.00 sep 18.1 mag 9.82,9.98 Sp K0 dist. 46.64 pc (152.14 l.y.)

STF2141 AB: 152; 125x: White stars, nearly 2 Dm, it is in the middle of a slightly bent line of three bright stars.  -93% PRO, it is not binary.

17h 16m 36.95s +03° 24' 30.4" P.A. 123.00 sep 39.8 mag 8.32,10.72 Sp F8 dist. 82.1 pc (267.81 l.y.)

STF2143 AB: 152; 125x: 1 Dm, wide.  Rich star field.  -79% PRO, it is not binary.

17h 14m 50.00s +09° 59' 37.2" P.A. 120.00 sep 28.5 mag 9.11,10.89 Sp F8 dist. 819.67 pc (2673.76 l.y.)

STF2144 AB: 152; 125x: Wide, 1 Dm.  -94% PRO, it is not binary.

17h 17m 23.29s -07° 52' 09.0" P.A. 178.00 sep 25.9 mag 8.43,10.53 Sp K2 dist. 253.16 pc (825.81 l.y.)

STF2149 AB: 152; 125x: Faint near equal pair, nicely split.  53% PRO, 703 AU WS, 1.0+1.0 Msol, RVD 0.1 < EV2.2, it is likely binary and needs an orbit.

17h 19m 58.44s -06° 25' 44.5" P.A. 24.00 sep 7.3 mag 10.06,10.30 Sp G0

STF2150 AB: 152; 125x: Faint near equal pair, well split.  -97% PRO, it is not binary.

17h 21m 05.28s +01° 31' 53.2" P.A. 214.00 sep 11.7 mag 11.02,11.15 Sp F9V

STF2156 AB: 152; 125x: Pretty, unequal pair, close split.  -35% PRO, it is not binary.

17h 23m 57.34s -00° 50' 06.8" P.A. 36.00 sep 3.8 mag 8.95,9.50 Sp F2

STF2158 AB: 152; 125x: 1 Dm, wide.  41% PRO, 8,720 AU WS, 2.4+1.6 Msol.  The total system mass might make up for the very wide weighted separation, it might be binary and needs an orbit.

17h 24m 03.36s +03° 04' 03.4" P.A. 77.00 sep 23.4 mag 9.04,10.49 Sp A5V+F7III dist. 358.42 pc (1169.17 l.y.)

STF2166 AB: 152; 125x: Wide, slightly unequal white stars.  41% PRO, 3,225 AU WS, 2.0+1.5 Msol, RVD 1.1 < EV 1.4, it is likely binary and needs an orbit.

17h 27m 52.25s +11° 23' 25.8" P.A. 282.00 sep 27.2 mag 7.15,8.58 Sp A5V dist. 115.07 pc (375.36 l.y.)

STF2159 AB: 152; 125x: Wide, slightly unequal. -61% PRO, it is not binary.

17h 24m 54.75s +13° 19' 42.2" P.A. 325.00 sep 26.4 mag 8.53,9.44 Sp F8 dist. 30.98 pc (101.06 l.y.)

STF2169 AB: 152; 125x: Wide, slightly unequal.  -90% PRO, it is not binary.

17h 30m 00.00s -08° 24' 51.8" P.A. 110.00 sep 15.5 mag 8.93,10.38 Sp F8

STF2170 AB: 152; 125x: Faint pair, very closely split, unequal.  -23% PRO, it is not binary.

17h 28m 43.65s +10° 29' 03.5" P.A. 58.00 sep 3.3 mag 9.38,10.01 Sp G5

STF2171 AB: 152; 200x: Unequal, very close split with 125x, better 200x.  28% PRO, 176 AU WS, 1.6+1.5 Msol, it is possibly binary and needs an orbit.

17h 29m 16.68s -09° 59' 26.0" P.A. 60.00 sep 1.4 mag 8.33,8.50 Sp F2 dist. 114.94 pc (374.93 l.y.)

STF2172 AB: 152; 125x: Faint B, well split but needs averted vision to notice. 74% PRO, 1,240 AU WS, 1.5+0.8 Msol, but the RVD 2.3 > EV 1.8, it is not a bound pair.

17h 29m 56.26s -01° 18' 22.9" P.A. 171.00 sep 11.4 mag 8.55,11.46 Sp F2 dist. 106.5 pc (347.4 l.y.)

STF2176 AB: 152; 125x: Wide, slightly unequal.  -66% PRO, it is not binary.

17h 31m 06.48s +10° 26' 57.5" P.A. 17.00 sep 16.8 mag 9.53,10.32 Sp K0

STF2183 AB: 152; 125x: Wide, 1 Dm.  -40% PRO, it is not binary.

17h 35m 30.06s -05° 55' 53.6" P.A. 165.00 sep 29.6 mag 8.17,12.42 Sp A2Vn dist. 347.22 pc (1132.63 l.y.)

 

STF2184 AB: 152; 125x: Wide faint B seen with averted vision only.  -96% PRO, it is not binary.

17h 34m 21.99s +13° 09' 39.7" P.A. 66.00 sep 22.8 mag 6.63,11.60 Sp G8III dist. 146.2 pc (476.9 l.y.)

STF2185 AB: 152; 125x: Wide, 3 Dm.  36% PRO, 2,469 AU WS, 1.7+0.8 Msol, but the RVD 2.8 > EV 1.4, it is not binary.

17h 34m 48.53s +06° 01' 25.8" P.A. 5.00 sep 27.2 mag 7.46,10.32 Sp F8 dist. 91.07 pc (297.07 l.y.)

STF2186 AB: 152; 125x: Beautiful close split, unequal white stars. 2% PRO but 6% error, 1,222 AU WS, 2.9+2.9 Msol.  Given the mass and the weighted separation, there is some chance of it being binary, and an orbit should be tried.

17h 35m 50.43s +00° 59' 47.7" P.A. 78.00 sep 3.0 mag 8.23,8.43 Sp B8IV dist. 302.11 pc (985.48 l.y.)

STF2187 AB-C: 152; 125x: Lovely close unequal pair.  No parallax data for the primary.

17h 35m 40.75s +04° 08' 49.6" P.A. 178.00 sep 3.2 mag 9.10,10.05 Sp F2

STF2188 AB: 152; 125x: Slightly unequal, faint, well split.  68% PRO, 2,243 AU WS, 2.4+1.9 Msol, so it might be binary and needs an orbit.

17h 36m 14.69s +06° 37' 16.9" P.A. 203.00 sep 5.5 mag 9.22,9.98 Sp A5

STF2191 AB: 152; 125x: Wide 1 Dm, white.  41% PRO, 2,908 AU WS, 1.7+1.5 Msol, and the RVD 0.7 < EV 1.4, it is likely binary and needs an orbit.

17h 39m 47.28s -04° 58' 04.8" P.A. 267.00 sep 26.4 mag 7.83,8.47 Sp F2V dist. 140.45 pc (458.15 l.y.)

STF2193 AB: 152; 300x: Faint and too hazy to resolve at low power, needed higher power to separate and resolve the stars, well split slightly unequal. 0% PRO, 2,289 AU WS, 1.7+1.6 Msol, and the proper motion is similar -- so it might be binary and needs an orbit tried.

17h 41m 58.13s +08° 13' 53.5" P.A. 66.00 sep 5.9 mag 10.71,10.84 Sp F5+F1

STF2200 AB: 152; 200x: Very delicate split with 125x, best seen at 200, very closely split unequal stars.  64% PRO, 557 AU WS, 2.6+2.2 Msol, it is likely binary and needs an orbit tried.

17h 43m 51.66s +05° 50' 41.7" P.A. 163.00 sep 1.6 mag 8.50,9.18 Sp A0

STF2201 AB: 152; 200x: B appears only with high power and averted vision, well separated.  10% PRO, 3,635 AU WS, 3.3+1.7 Msol, but the RVD 3.4 > EV 1.6, it is not binary.

17h 44m 24.09s +02° 58' 02.3" P.A. 305.00 sep 7.8 mag 8.70,10.57 Sp K1II-III dist. 373.13 pc (1217.15 l.y.)

STF2202 AB: 60; 40x: Wide, near equal bright white stars.  -16% PRO, it is not binary.

17h 44m 34.09s +02° 34' 45.9" P.A. 93.00 sep 20.8 mag 6.13,6.47 Sp A1IV-V dist. 84.82 pc (276.68 l.y.)

STF2208 AB: 152; 125x: Well separated B see with averted vision then can hold directly.  -44% PRO, it is not binary.

17h 46m 32.58s -04° 28' 48.3" P.A. 275.00 sep 9.4 mag 9.79,11.60 Sp G0

STF2211 AB: 152; 125x: 1 Dm, wide.  41% PRO, 1,468 AU WS, 1.4+1.1 Msol, and the RVD 1.3 < EV 1.7, it is likely binary and needs an orbit tried.

17h 46m 39.40s -01° 12' 51.9" P.A. 116.00 sep 10.4 mag 9.21,10.62 Sp G0 dist. 105.82 pc (345.18 l.y.)

STF2212 AB: 152; 125x: Very delicate near equal close pair.  The 60mm finder scope shows it is in a large open cluster with many bright white scattered stars.  -3% PRO, it is not likely to be binary.

17h 46m 26.79s +05° 42' 01.3" P.A. 340.00 sep 3.3 mag 9.51,9.60 Sp A0

STF2216 AB: 152; 125x: Wide 2 Dm.  47% PRO, 9,324 AU WS, 2.8+1.7 Msol, there is some chance it's binary and needs an orbit.

17h 47m 02.17s +05° 41' 30.6" P.A. 27.00 sep 27.3 mag 8.01,10.09 Sp B8

STF2221 AB: 152; 125x: 1 Dm, wide, need averted vision to detect B. -92% PRO, it is not binary.

17h 48m 43.83s +01° 09' 51.1" P.A. 76.00 sep 19.5 mag 8.95,11.14 Sp G5 dist. 373.13 pc (1217.15 l.y.)

STF2223 AB: 152; 125x: Wide, white, 2 Dm.  10% PRO, 1,877 AU WS, 1.8+1.1 Msol, but the RVD 2.0 > EV 1.6, it is not binary.

17h 48m 57.84s +04° 58' 03.2" P.A. 211.00 sep 18.3 mag 7.56,9.66 Sp F0V dist. 86.51 pc (282.2 l.y.)

STF2227 AB: 152; 125x: Near equal faint stars, well split.  -96% PRO, it is not binary.

17h 49m 22.00s +05° 20' 19.0" P.A. 110.00 sep 15.1 mag 9.55,9.60 Sp G:+A6

STF2228 AB: 152; 125x: Faint, wide, near equal.  -66% PRO, it is not binary.

17h 49m 34.44s +09° 11' 29.5" P.A. 106.00 sep 19.0 mag 10.55,10.87 Sp K0

STF2230 AB: 152; 125x: Wide 1 Dm. -97% PRO, it is not binary.

17h 50m 40.12s +07° 55' 18.8" P.A. 87.00 sep 46.8 mag 9.21,9.85 Sp A2

STF2231 AB: 152; 125x: Wide 1 Dm.  -93% PRO, it is not binary.

17h 51m 01.06s +12° 12' 48.2" P.A. 153.00 sep 32.3 mag 9.02,11.59 Sp K0 dist. 980.39 pc (3198.03 l.y.)

STF2233 AB: 152; 200x: Lovely close pair, 2 Dm, split with low but better seen 200x.  -9% PRO, not likely binary.

17h 51m 52.55s +02° 53' 59.4" P.A. 66.00 sep 2.3 mag 8.30,10.55 Sp A0 dist. 249.38 pc (813.48 l.y.)

STF2234 AB: 152; 125x: Wide, near equal.  0% PRO, it is not likely binary.

17h 52m 43.98s -07° 56' 54.2" P.A. 199.00 sep 16.6 mag 9.85,10.68 Sp G5

STF2235 AB: 152; 125x: Wide 1 Dm, light yellow stars.  -65% PRO, it is not binary.

17h 52m 59.39s -02° 15' 26.8" P.A. 124.00 sep 20.2 mag 8.49,9.95 Sp G8 dist. 1351.35 pc (4408.1 l.y.)

STF2240 AB: 152; 200x: Super fine faint pair, slightly unequal, close, split at 125x better at 200x.  69% PRO, 571 AU WS, 1.2+1.4 Msol, it is likely binary and needs an orbit.

17h 53m 33.99s +05° 15' 46.0" P.A. 204.00 sep 3.0 mag 9.90,10.60 Sp G0

STF2244 AB: 152; 350x: Very pronounced snowman, but not split.  No Gaia data for the secondary.  SOC grade 3 orbit, 474.9-year period, it will hand in the SE for the next couple of decades.

17h 57m 04.32s +00° 04' 00.0" P.A. 100.50 sep 0.7 mag 6.89,6.56 Sp A3V dist. 118.48 pc (386.48 l.y.)

STF2250 8.8/9.2 7.8": = STF2249. Lovely white near equal stars, well separated.  -27% PRO, it is not binary.

17h 59m 18.09s -06° 51' 21.2" P.A. 344.00 sep 7.8 mag 8.79,9.24 Sp B9 dist. 645.16 pc (2104.51 l.y.)

STF2252 AB: 152; 125x: Nice close pair, near equal, white stars.  -66% PRO, it is not binary.

17h 59m 01.63s +02° 02' 16.2" P.A. 24.00 sep 4.0 mag 8.64,9.02 Sp A2 dist. 327.87 pc (1069.51 l.y.)

STF2254 AB: 152; 125x: Excellent near equal white pair.  Very faint C seen with the opposite PA. 8% PRO, 957 AU WS, 2.0+1.9 Msol, and the RVD 0.1 < EV 2.7, it might be binary and needs an orbit.

17h 59m 00.91s +12° 26' 18.5" P.A. 266.00 sep 3.5 mag 9.11,9.31 Sp A2

α Virginis Nebula and other wonders

In order to explore more of the large gas structures of our Milky Way, I have started to use the Finkbeiner H-alpha all-sky map as my atlas.  I've printed out sections of it by constellation so I can refer to it as I explore all the wisps and tendrils which connect all the familiar (and not so familiar) nebula with my night vision device.  One area which caught my attention a couple months ago was a cloud floating above the plane of the Milky Way somewhere to the northwest of Scorpio.  It's pointed out here and looks like an eye with an eyebrow.  It is considerably fainter than Sivan 10, which is in turn considerably fainter than Sh2-27, which is a difficult object visually but which many a night vision device user has discovered by panning around the sky.  

While on the Finkbeiner Gas line layer in Aladin, I navigated to the spot but at first there was no nebula seen.  I needed to adjust Aladin's pixel mapping (like adjusting the contrast on a TV) to make it appear.  To my shock I found the nebula is more or less centered on Spica, Alpha Virginis.  This is what it looks like:

It is enormous, roughly 20-degrees W-E by 18-degrees N-S--larger than the main star grouping of Corvus.  In the Finkbeiner image it appears to be either lit from below (from the main plane of the Milky Way) or perhaps even illuminated by Spica itself?  I have no idea of its distance and don't find a designation for it.  Curiously, there is a noticeable lack of galaxies plotted in atlases in this region of Virgo -- I wonder if they are being obscured by this cloud?

I first tried to view this during the May new moon from a site in San Benito County.  I only used 1x (ie. no magnification, just looking through the device) and a 7nm Ha filter.  I used a mirror mount to hold the device steady.  I made a sketch of what I perceived as a very excessively faint wash of nebula south of Spica.  Mark Wagner, who was with me, sketched nearly the same view, but he was more confident in his observation than I was of mine.  I needed to try again to be sure.

Monday night I went up to Williams Hill and found a turnout on the road to the tower.  It was very windy and cold, mid- to low- 40s.  Fortunately, I came dressed for it, but it was disconcerting to observe in winter-like conditions during the summer.  I brought a NP-101 (4-inch refractor, 4-degree FOV), a 60mm f/5 refractor (8-degree FOV), and my mirror mount and a monopod to view 1x (40-degree FOV).  I also printed a finder chart of the nebula from Aladin with the coordinate grid included, so I could use my alt/az mount's DSC to locate specific parts of the nebula.  During the hour I observed it my SQML read between 21.2-21.4 -- transparency was not as good as expected. 

Once dark I pointed my 4-inch to what looks like the brightest part, at approximately RA 13:40 Dec -15:00.  I set the device's gain quite low (which darkens the sky and stars but gives more contrast for the nebula).  As I flipped my filter wheel from unfiltered to a 3nm Ha, I immediately saw an expanse of very faint mottled nebulosity.  It was like blinking an OIII filter to see a planetary nebula: at first, it's not there and then--add the filter, and there it is.  The nebula faded from view, so I had to flip back and forth between unfiltered and filtered to get used to seeing it -- eventually I could pick it out against the sky background regularly.  In this area, the north was weaker of nebulosity, but it filled the eastern, western, and southern parts of the field, and beyond the edge of the field as I panned.  This is as should be expected.

I tried some other areas, such as the NW corner centered at RA 13:00 Dec -10:00.  Just as before, the nebula appeared when flipping from unfiltered to filtered.  Weak nebula to the north, less faint to the west, and stronger east and south.  Next I switched to the 60mm, and brought it back to the brightest section in the SE.  The nebula was quite strong in this entire quadrant, and I followed a loop to the east back up to Spica.  Both the Ha+OIII and OIII filters showed different aspects of the nebula.  I also looked at the "Eyebrow" portion centered RA 14:14 Dec -5:23 and found a very faint E-W wisp and a stronger N-S stream in the east of the field.  All as expected.  

Finally, I mounted the device on the monopod and scanned the area.  This time I had less difficulty seeing the southern portion of the nebula (I could not see the eyebrow), and more confidently sketched it.  I scanned over to Sh2-27 and judged its brightness against Siv 10, and then panned over to the Alpha Virginis nebula.  While the entire extent of the nebula is fainter than Siv 10, the brightest pocket to the SE of Spica is actually not very difficult.  

Sivan 8: After taking a break and basking in the triumph I continued with more.  I've been really fascinated by Sivan 8, at the base of Scorpio's tail.  With the 60mm and Ha I could see the entire "wheel" shape with IC4628 shining brightly, along with the column of nebula which divides the wheel N-S near the center.   In Finkbeiner's image there is a very faint parenthesis of wispy nebula beyond the southeastern curve of Siv 8, and I had the strong sense I was picking it up.  Williams Hill itself was disrupting the view, so I will need to come back to this area.  There's also a "pillar" in the western arc of Siv 8, but I was disorientated a little and did not see it.

Cassiopeia "C":  Later in the night I tried for another feature I noticed, a large "C" shaped nebulosity which flows down from IC59/63 to the east south toward NGC281 (aka "Pacman").  It was faint but once seen I could make out some wispy detail.  I tried hard for the opposite parenthesis stream flowing along the west, but could not make it out.  

The rest of the night was spent panning around at various familiar objects in Cygnus and along the plane of the Milky Way, with Ha and also with the longpass filter to see dark nebula and endless stars.  Such observing doesn't lend itself to much formal reporting.  The experience is far too spiritual, without words, to be able to pin down.  Wonderous.

16 june 2023 short period pairs

Seeing was forecast to be above average last night so I opened up the 20-inch.  Though it wasn't excellent I did go after some short period binaries on my "movement" list with decent success.  After a couple hours observing I felt I had a good enough night, and since seeing wasn't getting any better decided to pack it in.

STT 298 C; 203; 280x: Easy split, near equal light orange stars, PA SSW, with a similar magnitude star near to mark PA.  20% PRO, 25 AU WS, 0.8+0.9 Msol, certainly binary.  SOC grade 1 orbit 55.42-year period, it will close slowly to the west by 2042.

15h 36m 02.22s +39° 48' 08.9" P.A. 190.50 sep 1.2 mag 7.16,8.44 Sp K2V dist. 22.31 pc (72.78 l.y.)

HU 1168 AB: 508; 600x: Extremely fine split, light orange stars, PA WNW, with seeing.  -49% PRO, through 32 AU WS, 0.8+0.9 Msol, SOC grade 3 orbit 88.57-year period.  If it is a true binary it will close to the SW in the 2040s. 

15h 37m 00.37s +64° 26' 23.3" P.A. 285.10 sep 0.5 mag 9.48,9.73 Sp G5 dist. 55.71 pc (181.73 l.y.)

JEF1 AB: 508; 1270x: Using all my highest powers, a blue filter, and an apodising mask, I can see an out of round olive dancing in the diffraction, but could not tell consistent PA.  SOC grade 1 orbit, 10.54-year period, it is coming off periastron now and will be at apastron 0.314" in 2028, certainly one to keep an annual watch on.  No Gaia data on the secondary.

15h 27m 49.85s +29° 06' 19.8" P.A. 114.90 sep 0.1 mag 3.68,5.20 Sp A5+F2 dist. 34.28 pc (111.82 l.y.)

STF1937 AB: 508; 560x: Eta CrB. Nice clean split, light orange stars PA NNW.  SOC grade 1 orbit, 41.63-year period, it will widen to the NE by 2035 periastron.  No Gaia data for the secondary.

15h 23m 12.23s +30° 17' 17.7" P.A. 305.40 sep 0.4 mag 5.64,5.95 Sp F8V+G0V dist. 17.86 pc (58.26 l.y.)

STF2084 AB: 203; 280x: Zeta Her.  Using a blue filter to suppress bright A's diffraction, tiny B sits as a sharp, defined point just outside of A's first diffraction ring, very much fainter, east PA. No Gaia parallax data.  SOC grade 1 orbit 34.46-year period, at apastron now, it will slowly close to the NE by 2030 then have a quick periastron around 2035 at around 0.3".

16h 41m 17.16s +31° 36' 09.8" P.A. 100.00 sep 1.5 mag 2.95,5.40 Sp G1IV dist. 10.72 pc (34.97 l.y.)

STF1909 AB: 508; 580x: 44 Boo.  With 8-inch, a strongly notched elongation, PA to S.  With 20-inch and 580x and 850x it is split, light orange stars, noticeable difference in magnitudes.  SOC grade 2 orbit, 214.7-year period, it is coming off periastron now and will widen from the current 0.391" to around 2.5" in 2040 and >4" by 2080.  No Gaia parallax data for the primary.

15h 03m 47.30s +47° 39' 14.6" P.A. 141.70 sep 0.2 mag 5.20,6.10 Sp F7V+K4V dist. 12.51 pc (40.81 l.y.)

3 june 2023

Seeing was rather good throughout the day.  I had an hour's observing with the 6-inch solar, with finely detailed sunspots in several groups, and many interesting prominences.  I observed with the 20-inch at night, with seeing forecast to be excellent later in the night.  It started out ok, but I masked down and went after some Struves before trying some challenge pairs.  I've had some instability with the ServoCAT where it seems to lose its programming and slews in the wrong way.  I revived an old computer which had the ServoCAT utility software and reloaded my settings.  But late in the night the goto slew went in the wrong direction again, so I packed it in.  There were high thin clouds out throughout the night, so it was no loss to pack it in.  Before going inside I uncovered the 6-inch again and used the 60mm on the full moon.  It was really amazing--very fine detail and the image was sharp and clear, and despite the haze all aournd the moon, in this scope the sky around the moon was pitch black.  What fun, and I'm so glad I spent the extra half hour.

STF1744 AB: 178; 125x: Mizar.  Bright, wide pair, white stars, very pleasing view with smaller aperture.  86% PRO, 359 AU WS, 2.8+2.0, likely binary needs an orbit. 

13h 23m 55.42s +54° 55' 31.5" P.A. 153.00 sep 14.6 mag 2.23,3.88 Sp A1VpSrSi dist. 26.31 pc (85.82 l.y.)

STF1603 AB: 178; 125x: Light yellow-orange stars, near equal.  -19% PRO, it is not likely to be binary.

12h 08m 07.07s +55° 27' 50.7" P.A. 83.00 sep 22.2 mag 7.82,8.26 Sp F8V+F9V dist. 49.07 pc (160.07 l.y.)

STF1630 AB: 178; 300x: Beautiful, faint close pair of light orange stars, half delta magnitude, close split with 150x, better seen at 300x.  -5% PRO, it is not likely binary.

12h 18m 53.81s +56° 22' 06.0" P.A. 171.00 sep 2.5 mag 9.50,10.26 Sp G0 dist. 105.71 pc (344.83 l.y.)

STF1608 AB: 178; 125x: Near equal, light orange, wide.  84% PRO, 381 AU WS, 0.9+0.8 Msol, it is likely binary and needs an orbit.

12h 11m 27.76s +53° 25' 17.5" P.A. 220.50 sep 13.6 mag 8.11,8.27 Sp K0 dist. 30.15 pc (98.35 l.y.)

STF1600 AB: 178; 125x: Very light-yellow stars, noticeable delta magnitude, well split.  -52% PRO, it is not binary.

12h 05m 34.42s +51° 55' 52.2" P.A. 92.00 sep 7.8 mag 7.63,8.28 Sp G8III dist. 369 pc (1203.68 l.y.)

STF1601 AB: 178; 200x: ! Very delicate, faint, blue-white A and light-orange B, 1 Dm, closely split, suspect with 125x, better seen with higher power to brighten the faint B star.  23% PRO, 162 AU WS, 1.0+0.8 Msol, so there is some chance it is binary and needs an orbit tried.

12h 06m 08.63s +38° 49' 42.4" P.A. 298.00 sep 2.0 mag 9.64,10.80 Sp G6IV dist. 113.77 pc (371.12 l.y.)

STF1594 AC: 178; 125x: 1 Dm, well split.  -47% PRO, it is not binary.

12h 03m 28.56s +41° 24' 15.5" P.A. 142.00 sep 11.0 mag 10.09,11.10 dist. 129.53 pc (422.53 l.y.)

STF1589 AB: 178; 200x: Excellent close pair, noticeable delta, closely split, white.  Split with 125x, better seen with 200x. -61% PRO, it is not binary.

12h 00m 36.34s +43° 37' 19.1" P.A. 159.00 sep 2.2 mag 10.19,10.40 Sp F8

STF1592 AB: 178; 125x: Wide, faint B seen with averted vision only.  -43% PRO, it is not binary.

12h 02m 21.01s +35° 37' 41.2" P.A. 275.00 sep 25.6 mag 10.99,11.30 Sp F8

STF1770 AB: 178; 200x: Very pretty orange A and light blue B, >1 Dm, close but nicely split, split with 125x but better seen with 200x.  -60% PRO, it is not binary.

13h 37m 42.92s +50° 42' 53.5" P.A. 123.00 sep 1.7 mag 6.93,8.18 Sp K3III: dist. 434.78 pc (1418.25 l.y.)

STF1662 AB: 178; 200x: Light yellow-orange A, wide 2 Dm B.  -49% PRO, it is not binary.

12h 35m 48.64s +56° 34' 42.4" P.A. 243.00 sep 19.3 mag 7.83,9.75 Sp K0III dist. 167.22 pc (545.47 l.y.)

STF1660 AB: 178; 125x: Unremarkable wide pair, nearly 1 Dm.  64% PRO, 3,863 AU WS, 1.4+1.1 Msol, and the RVD 1.1 is equal to the ES 1.1.  Might be binary, needs an orbit.

12h 34m 58.71s +58° 14' 16.3" P.A. 118.00 sep 19.7 mag 9.87,11.12 Sp F2 dist. 114.42 pc (373.24 l.y.)

STF1667 AB: 178; 300x: Very fine, half delta magnitude.  -52% PRO, it is not binary.

12h 39m 36.41s +64° 40' 27.2" P.A. 40.00 sep 1.2 mag 9.49,9.99 Sp F5 dist. 273.22 pc (891.24 l.y.)

STF1831 AB: 178; 125x: AC is wide bright near equal, -95% PRO and not binary.  AB is a 3 Dm close companion around 6" but -65% PRO, not binary.  Seven pairings in the system but none are binary.

14h 16m 08.47s +56° 42' 45.7" P.A. 138.00 sep 5.8 mag 7.16,9.56 Sp A7IV dist. 156.01 pc (508.9 l.y.)

STF1830 CE: 178; 125x: 2 Dm very wide, not binary, -95% PRO.

14h 15m 59.89s +56° 41' 20.8" P.A. 245.00 sep 138.2 mag 6.73,9.33 Sp F8V dist. 48.31 pc (157.59 l.y.)

STF1800 AB-C: 178; 125x: Easy wide 2 Dm pair.  No parallax data for the primary.

14h 02m 00.60s +57° 13' 28.6" P.A. 20.00 sep 28.4 mag 7.76,10.42 Sp F5 dist. 146.63 pc (478.31 l.y.)

A1097 AB: 508; 800x: Clean split, nearly one delta.  No parallax data for the primary.

14h 02m 00.60s +57° 13' 28.6" P.A. 260.50 sep 0.4 mag 9.09,8.24 Sp F5 dist. 146.63 pc (478.31 l.y.)

STT 269 AB: 508; 800x: Can only see as single, all powers.  53.2-year period grade 2, it is coming off apastron and will close to periastron in 2040, not visible again until the 2050s-60s.  No Gaia parallax data for either star.

13h 32m 51.02s +34° 54' 25.8" P.A. 228.20 sep 0.3 mag 7.27,8.08 Sp A6III dist. 147.93 pc (482.55 l.y.)

HU  644 AB: 508; 300x: Faint pair, significant delta magnitude, white, well split, it is very close to us at 10.71 parsecs.  No Gaia parallax data for either star. SOC grade 2 orbit, 48.776-year period, it will make a quarter turn to the west by 2030 then be due south by 2045.  Somehow my PA is reversed from the published data.

13h 19m 45.58s +47° 46' 41.1" P.A. 280.40 sep 0.5 mag 9.11,9.87 Sp M2V dist. 10.71 pc (34.94 l.y.)

18 may 2023

Observed through the 6-inch, with a few viewed with the 60mm.  Seeing was forecast to be better than it was.  With it staying lighter later, there was less time to observe.  Izar appeared best through the 60mm through medium to high magnification -- even in the 6-inch there was significant flaring of the primary.  I'm glad I added the 60mm to my repertoire. 

STF1691 AB: 152; 125x: 1 Dm, wide.  99% PRO, 2,660 AU WS, 1.6+1.2 Msol, and the 1.1 RVD vs 1.4 ES indicates it's binary, and an orbit should be tried.

12h 54m 59.60s +58° 09' 37.6" P.A. 276.00 sep 18.7 mag 8.58,9.80 Sp F0IV dist. 68.17 pc (222.37 l.y.)

STF1785 AB: 152; 125x: Suspected double in the 60mm scope, in the 6-inch they are pretty light orange stars, 1 Dm, closely split.  47% PRO, 40 AU WS, 0.7+0.6 Msol, it is binary and has a SOC grade 2 orbit, 156-year period.

13h 49m 04.00s +26° 58' 47.7" P.A. 191.40 sep 2.7 mag 7.36,8.15 Sp K4V+K6V dist. 13.41 pc (43.74 l.y.)

STF1779 AB: 152; 300x: Faint, visible with seeing and high power, white stars, separated, nearly 1 Dm.  88% PRO, 1,135 AU WS, 2.0+1.5 Msol, it is likely binary and needs an orbit.

13h 44m 33.98s +23° 40' 06.0" P.A. 145.00 sep 3.8 mag 9.26,10.37 Sp A5 dist. 775.19 pc (2528.67 l.y.)

STF1772 AB: 152; 125x: Bright white and quite a bit fainter B, closely separated, but wide enough for the large delta mag not to be a problem.  -13% PRO, so in spite of the other factors (447 AU WS, 2.5:1.1 Msol), it is not likely binary.

13h 40m 40.50s +19° 57' 20.4" P.A. 133.00 sep 4.4 mag 5.76,9.60 Sp A1V dist. 100.6 pc (328.16 l.y.)

STF1782 AB: 152; 125x: Wide, 1 Dm, light yellow A and blue B. -32% PRO, it is not binary.

13h 45m 06.87s +18° 22' 04.3" P.A. 185.00 sep 30.4 mag 7.98,9.81 Sp F5

STF1773 AB: 152; 125x: B seen with averted vision only, wide.  -98% PRO, it is not binary.

13h 41m 38.19s +07° 36' 21.3" P.A. 209.00 sep 30.6 mag 9.95,10.00 Sp F7V

STF1792 AB: 152; 200x: B seen with averted vision, need higher powers to see it and split from A.  -50% PRO, it is not binary.

13h 57m 03.72s +12° 27' 03.5" P.A. 291.00 sep 2.3 mag 9.98,10.89 Sp F8 dist. 1470.59 pc (4797.06 l.y.)

STF1791 AB: 152; 125x: Wide, nearly 1 Dm.  No parallax data for the primary.

13h 56m 49.22s +14° 25' 58.6" P.A. 159.00 sep 21.0 mag 9.39,10.73 Sp F7V+G1IV

STF1794 AB: 152; 300x: Excellent pair, white stars, significant delta, suspected with 125x, suspected 125x, split 200x, best 300x, with seeing.  73% PRO, 252 AU WS, 1.3+1.2 Msol, it is likely binary and needs an orbit.

13h 59m 48.26s +19° 52' 57.8" P.A. 125.00 sep 1.8 mag 9.48,9.65 Sp F8 dist. 151.29 pc (493.51 l.y.)

STF1793 AB: 152; 125x: Lovely cream-colored A and yellow B, close separation, 1 Dm.  1% PRO, 85 AU WS, 2.3+1.8 Msol, there is some chance it is binary, and an orbit should be tried.

13h 59m 05.25s +25° 48' 57.6" P.A. 243.00 sep 4.8 mag 7.46,8.39 Sp A5V dist. 153.61 pc (501.08 l.y.)

STF1839 AB: 152; 125x: Near equal, wide.  42% PRO, 1,989 AU WS, 1.5+1.5 Msol, and 0.1 RVD vs 1.7 EV, indicates it is binary and an orbit is needed.

14h 21m 27.38s +53° 53' 50.9" P.A. 83.00 sep 14.5 mag 8.84,8.92 Sp G0 dist. 178.89 pc (583.54 l.y.)

STF1821 AB: 152; 125x: Yellow A and blue B, wide, 2 Dm.  No parallax data for the secondary.

14h 13m 29.00s +51° 47' 23.8" P.A. 235.00 sep 13.8 mag 4.53,6.62 Sp A7V+F1V dist. 50.1 pc (163.43 l.y.)

STF1871 AB: 152; 125x: Very fine near equal light orange stars, closely split.  -75% PRO, it is not binary.

14h 41m 35.50s +51° 23' 51.3" P.A. 313.10 sep 1.9 mag 8.02,8.07 Sp F3V dist. 99.3 pc (323.92 l.y.)

STF1889 AB: 152; 125x: Pretty pair, white A and dull white B, nearly 1 Dm, wide.  -98% PRO, it is not binary.

14h 49m 32.37s +51° 22' 28.2" P.A. 93.00 sep 15.1 mag 6.53,9.64 Sp F3V dist. 57.11 pc (186.29 l.y.)

STF1829 AB: 152; 125x: Excellent pair, white stars, nearly 1 Dm, good close split.  27% PRO, 825 AU WS, 1.9+1.6 Msol, and 0.7 RVD vs 2.7 EV, it is likely binary and needs an orbit.

14h 15m 27.95s +50° 26' 24.6" P.A. 151.00 sep 5.6 mag 8.10,8.63 Sp F5 dist. 160.51 pc (523.58 l.y.)

STF1814 AB: 152; 125x: Near equal white stars, wide.  83% PRO, 1,304 AU WS, 1.3+1.1, RVD 0.6 vs EV 1.8, it is likely binary and needs an orbit.

14h 11m 00.99s +50° 15' 08.3" P.A. 256.00 sep 11.2 mag 9.25,9.83 Sp G5+G5

STF1890 AB: 152; 125x: Wonderful near equal yellow-white stars, tightly split with low power.  36% PRO, only 185 AU WS, 1.9+1.8 Msol, so it is likely binary.  Grade 4 SOC orbit.

14h 49m 41.37s +48° 43' 15.6" P.A. 46.00 sep 2.5 mag 6.31,6.67 Sp F6V+F5V dist. 68.59 pc (223.74 l.y.)

STF1834 AB: 152; 200x: Split at 125x, better viewed with 200x, 1 Dm closely split pair, really nice.  -12% PRO, it is not binary.

14h 20m 17.60s +48° 30' 25.1" P.A. 103.50 sep 1.6 mag 8.09,8.29 Sp F9V dist. 75.36 pc (245.82 l.y.)

16 may 2023

Observed with the 6-inch through average seeing and worsening transparency.  Still a lot seen, mostly in the south: 

STF1604 AB: 152; 125x: Very pretty triple star, forming a nearly equilateral triangle, light orange stars, the brightest >1 Dm than the next brightest, which is a half magnitude brighter than C.  Seen with the 60mm too.  AB do no share any parallax range overlap, -99%.  AC have -3% parallax range overlap, though the other specs (231 AU weighted separation, 1.0+0.6 Msol, 2.0 RVD vs. 3.5 EV) indicate binary they are all likely a line of sight asterism.

12h 09m 28.54s -11° 51' 25.4" P.A. 88.00 sep 9.0 mag 6.86,10.00 Sp G3V dist. 22.22 pc (72.48 l.y.)

 

STF1659 AB: 152; 125x: Quite the asterism: one large equilateral triangle composed of to equal magnitude white stars and one slightly unequal.  Inside this is a pointed triangle of slightly fainter stars, the two closest together are near equal magnitude and the point star 1 Dm.  The two closest stars of the inner triangle have the closest parallax, but they do not overlap, -64%.  It remains a very entertaining asterism.

12h 35m 43.75s -12° 01' 30.0" P.A. 351.00 sep 28.1 mag 7.94,8.34 Sp G0 dist. 144.51 pc (471.39 l.y.)

STF1669 AB: 152; 125x: Near equal light orange stars, close but easily split with low power.  A faint star well separated forms a pointed triangle with the main pair.  -66% parallax range overlap, it is not binary.

12h 41m 16.22s -13° 00' 53.6" P.A. 314.00 sep 5.3 mag 5.88,5.89 Sp F5V+F5V dist. 78.93 pc (257.47 l.y.)

STF1631 AB: 152; 125x: 3 Dm, wide, white stars.  -97 parallax range overlap, it is not binary.

12h 20m 09.95s -14° 07' 31.9" P.A. 305.00 sep 14.8 mag 8.38,10.95 Sp G1/2V dist. 60.75 pc (198.17 l.y.)

STF1618 AB: 152; 125x: Identical white stars, well separated.  -19% parallax range overlap, it is not binary.

12h 15m 03.46s +09° 59' 27.1" P.A. 245.00 sep 26.0 mag 9.46,9.46 Sp F5+F5 dist. 170.36 pc (555.71 l.y.)

STF1628 AB: 152; 125x: Near equal white stars, wide.  18% parallax range overlap, 1,428 AU weighted separation, 1.4+1.2 Msol, and 0.5 RVD vs 1.8 ES, it might be binary and need an orbit tried.

12h 18m 42.90s +11° 47' 46.3" P.A. 239.00 sep 9.5 mag 9.52,10.11 Sp G0 dist. 102.46 pc (334.22 l.y.)

STF1612 AB: 152; 125x: Faint pair, closely split, seen with direct vision, nice, with seeing.  72% overlap of the parallax ranges, 1,175 AU weighted separation, 1.3+1.2 Msol, and 0.6 RVD vs. 1.9 ES, it is likely binary and needs an orbit tried.

12h 12m 34.50s +10° 46' 18.2" P.A. 7.00 sep 5.6 mag 10.45,10.97 Sp G0

STF1619 AB: 152; 125x: Near equal light-yellow stars, well split, with a very wide faint C.  -12% parallax range overlap, it is not binary, in spite of the grade 5 orbit in SOC.

12h 15m 06.57s -07° 15' 26.4" P.A. 265.20 sep 6.8 mag 8.06,8.30 Sp G5 dist. 35.19 pc (114.79 l.y.)

STF1635 AB: 152; 125x: Unequal white stars, well split, with a wider, fainter C.  -37% parallax range overlap, it is not binary.

12h 21m 08.47s -11° 28' 32.7" P.A. 173.00 sep 13.4 mag 8.62,9.72 Sp B9V dist. 67.25 pc (219.37 l.y.)

STF1636 AB: 152; 125x: Brilliant white primary and 2 Dm fainter wide B.  There is 54% parallax range overlap, 625 AU weighted separation, 1.2+0.7 Msol, and 2.2 RVD vs. 2.3 ES, it may be binary and needs an orbit tried.

12h 22m 32.14s +05° 18' 20.1" P.A. 338.00 sep 21.0 mag 6.53,9.31 Sp F8V dist. 29.92 pc (97.6 l.y.)

STF1647 AB: 152; 200x: Excellent near equal pair, split with 125x but best seen at 200x. There is -8% parallax range overlap, so in spite of the 130 AU weighted separation, 1.4+1.5 Msol, and the grade 4 SOC orbit, it might not be binary.

12h 30m 33.75s +09° 42' 56.4" P.A. 249.50 sep 1.3 mag 8.09,8.37 Sp F2 dist. 92.51 pc (301.77 l.y.)

STF1648 AB: 152; 125x: Light yellow and light blue stars, good close split.  54% overlap of the parallax ranges, 2,329 AU weighted separation, 3.1+1.7 Msol, the 2.8 RVD is greater than the 1.9 ES, indicating not binary.

12h 30m 34.42s +03° 30' 29.6" P.A. 40.00 sep 8.1 mag 7.54,9.78 Sp G8III dist. 337.84 pc (1102.03 l.y.)

STF1649 AB: 152; 125x: Near equal white stars, wide.  19% overlap of the parallax ranges, 2,045 AU weighted separation, 1.8+1.6 Msol, and 0.3 RVD vs. 1.7 ES indicate it's binary and needs an orbit.

12h 31m 36.46s -11° 04' 20.2" P.A. 194.00 sep 15.7 mag 7.97,8.43 Sp A7 dist. 87.64 pc (285.88 l.y.)

STF1658 AB: 152; 150x: Close split, 1 Dm, light orange and light blue stars, very pretty.  75% PRO, 167 WS, 1.2+0.9 Msol, very likely binary and SOC provides a grade 4 obit, 1797-year period.

12h 35m 07.88s +07° 26' 34.6" P.A. 20.90 sep 2.8 mag 8.08,10.52 Sp F8 dist. 69.54 pc (226.84 l.y.)

STF1661 AB: 152; 200x: Beautiful close pair, near equal.  -40% PRO, it is not binary.  

12h 35m 57.59s +11° 24' 19.2" P.A. 254.00 sep 2.3 mag 9.21,9.24 Sp G2V dist. 84.75 pc (276.45 l.y.)

STF1664 AB: 152; 125x: A long "L" shaped asterism with a prominent orange star at the joint.  -97% PRO, it is not binary.

12h 38m 19.95s -11° 31' 01.1" P.A. 223.00 sep 38.7 mag 7.82,9.17 Sp K0 dist. 917.43 pc (2992.66 l.y.)

STF1665 AB: 152; 125x: Near equal stars, wide.  41% PRO, 382 WS, 0.8+0.7 Msol, 0.4 RVD vs. 2.7 ES, it is likely binary and needs an orbit.

12h 38m 44.27s -05° 19' 39.6" P.A. 102.00 sep 8.6 mag 9.06,9.71 Sp K0 dist. 41.44 pc (135.18 l.y.)

STF1668 AB: 152; 300x: Elongated at lower powers, need 300x to split, unequal white stars.  36% PRO, 122 WS, 1.7+1.5 Msol, it is likely binary and needs an orbit.

12h 40m 54.13s +08° 49' 45.2" P.A. 187.00 sep 1.1 mag 7.78,8.10 Sp F5V dist. 121.07 pc (394.93 l.y.)

STF1670 AB: 152; 200x: Porrima. Light orange stars, near equal, nicely split low and high power, able to split with 60mm too at high power.  No parallax data for the secondary.

12h 41m 39.60s -01° 26' 57.9" P.A. 356.20 sep 3.0 mag 3.48,3.53 Sp F0V+F0V dist. 11.68 pc (38.1 l.y.)

STF1673 AB: 152; 125x: Wide pair, 2 Dm. -40% PRO, it is not binary.

12h 42m 56.08s -02° 15' 04.0" P.A. 92.00 sep 53.6 mag 9.16,10.90 Sp K2V dist. 36.27 pc (118.31 l.y.)

STF1677 AB: 152; 125x: Unequal wide pair.  20% PRO, 3,103 WS, 2.6+2.0 Msol, 1.1 RVD vs 1.6 ES, it is likely binary and needs an orbit.

12h 45m 17.35s -03° 53' 17.0" P.A. 349.00 sep 16.1 mag 7.30,8.12 Sp A9IV dist. 262.47 pc (856.18 l.y.)

STF1682 AB: 152; 125x: Wide, 2 Dm, light orange A. -95% PRO, it is not binary.

12h 51m 22.92s -10° 20' 17.5" P.A. 299.00 sep 29.6 mag 6.59,9.69 Sp G8III dist. 156.01 pc (508.9 l.y.)

STF1683 AB: 152; 125x: Wide B seen with averted vision, then can hold direct.  -51% PRO, it is not binary.

12h 51m 40.35s -06° 07' 59.2" P.A. 197.00 sep 15.7 mag 8.45,10.69 Sp K0 dist. 490.2 pc (1599.03 l.y.)

STF1689 AB: 152; 125x: Pretty, light orange stars, wide, 1 Dm.  -95% PRO, it is not binary.

12h 55m 30.32s +11° 29' 46.4" P.A. 223.00 sep 30.2 mag 7.11,9.13 Sp M4III+F6V dist. 6.68 pc (21.79 l.y.)

STF1690 AB: 152; 125x: Blue-white A and rusty red B, 1 Dm, wide.  -81% PRO, it is not binary.

12h 56m 15.01s -04° 51' 50.3" P.A. 150.00 sep 5.8 mag 7.18,8.95 Sp A0V dist. 147.49 pc (481.11 l.y.)

STF1693 AB: 152; 125x: Near equal faint and well split pair. -12% PRO, it is not binary.

12h 56m 40.32s +07° 01' 11.8" P.A. 332.00 sep 8.7 mag 9.88,10.51 Sp G dist. 139.08 pc (453.68 l.y.)

27 april 2023

Observed with the 6-inch last night.  Seeing was good but there were thin high clouds -- or, I should say, typical Bay Area water vapor trapped overhead.  Star images were great.  I went after Struves mostly at zenith and toward Polaris, saving the more accessible pairs for later.  I also observed the pairs using the Tasco 60/1000, using a very nice Nikon zoom I bought.  It's converted from a spotting scope zoom and works very well, though it's a little heavy for the focuser, which was designed for 0.965" eyepieces.  Great views nonetheless.  After I was done with doubles after a couple hours of observing, I had a look at the half illuminated moon.  Wow.  I just love long focus refractors, the high contrast and sharpness is hard to beat.  Even though I can see more detail with the 20-inch, aesthetically, the refractors are so much more pleasing.

STF1544 AB: 152; 125x: 1 Dm, well separated.  There is -65% parallax range overlap, it is not binary.

11h 31m 18.57s +59° 42' 03.3" P.A. 91.00 sep 12.2 mag 7.33,8.02 Sp A3+Am dist. 588.24 pc (1918.84 l.y.)

STF1495 AB: 152; 125x: Light orange primary, >1 Dm, wide.  -94% parallax range overlap, it is not binary.

10h 59m 49.47s +58° 54' 23.3" P.A. 36.00 sep 34.2 mag 7.25,8.84 Sp K2II-III dist. 226.76 pc (739.69 l.y.)

STF1553 AB: 152; 125x: Pretty pair, closely split, near equal.  Was able to split it in the 60mm also.  -95% parallax range overlap, it is not binary, in spite of the SOC grade 4 orbit.

11h 36m 35.69s +56° 08' 07.3" P.A. 165.70 sep 6.2 mag 7.73,8.17 Sp G5+K7V dist. 46.99 pc (153.28 l.y.)

STF1546 AB: 152; 125x: Faint B seen with averted vision, then can hold direct, well split.  Only 1% parallax range overlap, 690 AU weighted separation, 1.4+0.7 Msol, the radial velocity delta 2.4 is just higher than the escape velocity 2.3, it is not likely binary.

11h 32m 20.34s +56° 05' 43.3" P.A. 349.00 sep 11.4 mag 7.54,10.30 Sp F8 dist. 56.69 pc (184.92 l.y.)

STF1572 AB: 152; 125x: Faint pair, well split.  47% parallax range overlap, 1,420 AU weighted separation, 1.3+1.0 Msol, and the radial velocity delta 1.1 is less than the escape velocity 1.7.  It is likely binary and needs an orbit.

11h 47m 00.74s +53° 17' 06.9" P.A. 289.00 sep 10.3 mag 9.46,10.79 Sp G dist. 160.26 pc (522.77 l.y.)

STF1510 AB: 152; 125x: Fairly closely split, 1 Dm, white stars.  29% overlap of the parallax ranges, 309 AU weighted separation, 1.3+0.9 Msol, and the radial velocity delta 1.3 is less than the escape velocity 3.6.  It is likely binary.  SOC grade 5 orbit 3156-year period.

11h 08m 00.06s +52° 49' 17.9" P.A. 327.70 sep 5.6 mag 7.65,9.03 Sp F8V dist. 55.96 pc (182.54 l.y.)

STF1520 AB: 152; 125x: Well split, 1 Dm, white stars, seen in 60mm also.  79% overlap of the parallax ranges, 482 AU weighted separation, 1.4+1.0 Msol, it might be binary and needs an orbit.

11h 16m 04.03s +52° 46' 23.4" P.A. 344.00 sep 12.4 mag 6.54,7.81 Sp F6V+F9V dist. 34.12 pc (111.3 l.y.)

STF1563 AB: 152; 125x: Wide, almost 1 Dm.   52% parallax range overlap, 1,377 AU weighted separation, 1.4+0.9 Msol, and the radial velocty delta 1.8 is just higher than the escape velocity 1.8.  It might be binary and needs an orbit.

11h 39m 23.55s +52° 11' 15.4" P.A. 157.00 sep 13.7 mag 8.58,10.64 Sp G0 dist. 83.47 pc (272.28 l.y.)

STF1587 AB: 152; 125x: B flashes with averted vision only, wide.  -15% overlap of the parallax ranges, it is not binary.

11h 59m 50.75s +51° 36' 59.9" P.A. 288.00 sep 16.8 mag 9.26,11.05 Sp G0 dist. 328.95 pc (1073.03 l.y.)

STF1562 AB: 152; 125x: Very faint pair, wide, B seen with averted vision.  -18% overlap of the parallax ranges, it is not binary.

11h 39m 13.51s +49° 09' 32.1" P.A. 270.00 sep 16.2 mag 9.76,11.60 Sp K0

STF1570 AB: 152; 125x: Well split near equal pair.  -48% overlap of the parallax ranges, it is not binary.

11h 45m 32.15s +45° 36' 13.1" P.A. 49.00 sep 10.9 mag 8.86,9.60 Sp F0 dist. 110.74 pc (361.23 l.y.)

STF1581 AB: 152; 200x: Very fine split, 1 Dm, split with 125x but better with higher power, nice.  -27% overlap of the parallax ranges, it is not binary.

11h 56m 06.32s +45° 32' 44.8" P.A. 171.00 sep 2.5 mag 9.80,10.44 Sp F8 dist. 381.68 pc (1245.04 l.y.)

STF1561 AB: 152; 125x: Light yellow, 1 Dm, well split, classic Struve.  -65% overlap of the parallax ranges, it is not binary in spite of the SOC grade 5 orbit.

11h 38m 44.90s +45° 06' 30.3" P.A. 245.50 sep 8.9 mag 6.53,8.23 Sp G0V dist. 23.25 pc (75.84 l.y.)

STF1574 AB: 152; 125x: Wide faint pair.  -18% overlap of the parallax ranges, it is not binary.

11h 51m 14.21s +44° 04' 49.7" P.A. 6.00 sep 9.4 mag 9.60,12.30 Sp G

STF1585 AB: 152; 125x: B seen with averted vision, well split.  86% overlap of the parallax ranges, 1,516 AU weighted separation, 2.3+1.4 Msol, but the radial velocity delta 2.4 is slightly more than the escape velocity 2.1, it may be physical but not remain binary, though an orbit should be tried.

11h 56m 40.53s +41° 01' 30.2" P.A. 106.00 sep 5.5 mag 8.79,11.08 Sp K0III dist. 386.1 pc (1259.46 l.y.)

STF1408 AB: 152; 125x: Fine pair, faint, <1 Dm, well split.  6% overlap of the parallax ranges, 481 AU weighted separation, 1.4+1.1 Msol, and the radial velocity detla 0.9 is less than the escape velocity 3.1.  It might be binary and needs an orbit tried.

10h 11m 21.83s +73° 02' 12.4" P.A. 14.00 sep 3.7 mag 9.01,9.98 Sp F2 dist. 137.17 pc (447.45 l.y.)

STF1393 AB: 152; 125x: Faint near equal pair, well split.  99% overlap of the parallax ranges, 3,386 AU weighted separation, 1.7+1.5 Msol, and the radial velocity delta 0.6 is less than the escape velocity 1.3.  It likely is binary and needs an orbit.

10h 01m 56.54s +73° 34' 07.1" P.A. 254.00 sep 9.7 mag 10.41,10.95 Sp F8 dist. 1492.54 pc (4868.67 l.y.)

STF1409 AB: 152; 125x: B seen with averted vision only, wide.  -79% parallax range overlap, it is not binary.

10h 15m 57.60s +79° 28' 10.0" P.A. 193.00 sep 19.3 mag 9.65,11.23 Sp F0 dist. 282.49 pc (921.48 l.y.)

STF1437 AB: 152; 125x: Near equal, very wide.  6% parallax range overlap, 2.2+1.1 Msol.  It might be binary and needs an orbit.

10h 34m 13.45s +73° 50' 04.1" P.A. 291.00 sep 23.4 mag 7.59,10.41 Sp A3 dist. 185.53 pc (605.2 l.y.)

STF1516 AC: 152; 125x: Closely split 2 Dm, B brightens with averted vision. 84% parallax overalap, only 95 AU weighted separation, 0.7+0.3 Msol, and the radial velocity delta 2.6 is less than the escape velocity 4.3, SOC grade 5 orbit 2774-year period. AB is not binary. 

11h 15m 11.91s +73° 28' 30.7" P.A. 103.00 sep 67.6 mag 7.77,8.23 Sp K5 dist. 14.65 pc (47.79 l.y.)

STF1551 AB: 152; 125x: Very faint B seen directly and brightens with averted vision.  81% overlap of the parallax ranges, 1,471 AU weighed separation, 1.9+1.2 Msol, and the radial velocity delta is the same as the escape velocity 1.9.  It may or may not remain binary, but an orbit should be tried.

11h 35m 18.37s +70° 48' 08.5" P.A. 111.00 sep 6.8 mag 9.02,10.80 Sp G5 dist. 258.4 pc (842.9 l.y.)

STF1573 AB: 152; 125x: Nice! significant delta magnitude, well split, seems to be in front of a faint cluster of stars, also seen with 60mm.  -21% overlap of the parallax ranges, it is not binary.

11h 49m 10.50s +67° 19' 42.8" P.A. 180.00 sep 10.9 mag 7.50,8.30 Sp G8III dist. 326.8 pc (1066.02 l.y.)

STF1410 AB: 152; 125x: Faint, nearly 1 Dm, well split.  41% overlap of the parallax ranges, 2,813 AU weighted separation, 2.0+1.2 Msol, but the radial velocity delta 2.2 exceeds the escape velocity 1.4, so it likely is not binary, though an orbit should be tried.

10h 37m 11.15s +86° 03' 28.3" P.A. 344.00 sep 14.4 mag 8.32,10.48 Sp F2

STF1654 AB: 152; 125x: White, 1 Dm stars, closely split.  Could split in 60mm with high power.  -11% overlap of the parallax ranges, it is not binary.

12h 32m 02.94s +74° 48' 41.5" P.A. 23.00 sep 3.8 mag 7.74,9.43 Sp G9III dist. 233.1 pc (760.37 l.y.)

STF1588 AB: 152; 125x: Slight delta mag, wide.  -97% parallax range overlap, it is not binary.

12h 02m 16.03s +72° 21' 43.1" P.A. 34.00 sep 11.7 mag 9.61,10.13 Sp K2 dist. 1369.86 pc (4468.48 l.y.)

STF1590 AB: 152; 125x: 2 Dm, closely split.  16% overlap of the parallax ranges, 979 AU weighted separation, 2.6+1.2 Msol, but the radial velocity delta 3.7 exceeds the escape velocity 2.6, it will not remain binary if it is so.

12h 01m 37.88s +70° 50' 59.6" P.A. 235.00 sep 5.4 mag 7.42,10.11 Sp K1III-IV dist. 157.23 pc (512.88 l.y.)

STF1626 AB: 152; 200x: Wonderful near equal white stars, split with 125x but better seen at 200x.  24% parallax range overlap, 354 AU weighted separation, 1.5+1.4 Msol, so it might be binary and needs an orbit.

12h 16m 47.11s +70° 08' 45.7" P.A. 2.00 sep 2.1 mag 9.37,9.55 Sp G0 dist. 157.98 pc (515.33 l.y.)

STF1602 AB: 152; 125x: Wide, 1 Dm, rather pretty.  -92% parallax range overlap, it is not binary.

12h 07m 07.57s +69° 04' 34.5" P.A. 180.00 sep 21.0 mag 8.27,9.91 Sp G5 dist. 90.42 pc (294.95 l.y.)

STF1599 AB: 152; 125x: The whole group is a lovely asterism, likely measured just for the fun of it to see if any change over time.  It's likely to be a co-moving group: AB has 52% overlap of the parallax ranges, 2,094 AU weighted separation, 2.7+1.1 Msol, but the radial velocity delta 4.8 far exceeds the escape veloctiy 1.8.

12h 05m 33.52s +68° 47' 39.7" P.A. 166.00 sep 10.1 mag 7.50,10.67 Sp K1III dist. 277.78 pc (906.12 l.y.)

STF1611 AB: 152; 125x: Very nice, very closely split with 200x, nearly 1 Dm.  41% parallax range overlap, 369 AU weighted separation, 1.7+1.2 Msol, so it might be binary and needs an orbit.

12h 11m 57.69s +68° 36' 10.5" P.A. 4.00 sep 1.9 mag 9.16,10.51 Sp F8

STF1614 AB: 152; 125x: Wide B is 2 Dm to the primary. -46% parallax range overlap, it is not binary.

12h 13m 07.94s +67° 04' 24.4" P.A. 191.00 sep 18.7 mag 8.65,11.29 Sp F8 dist. 106.38 pc (347.01 l.y.)

STF1640 AB: 152; 125x: Wide and faint B.  -98% parallax range overlap, it is not binary.

12h 24m 20.14s +63° 47' 36.0" P.A. 244.00 sep 37.9 mag 8.57,10.70 Sp K0 dist. 1162.79 pc (3793.02 l.y.)

STF1671 AB: 152; 125x: Faint near equal wide pair.  -32% parallax range overlap, it is not binary.

12h 41m 04.48s +68° 30' 57.9" P.A. 201.00 sep 29.0 mag 9.30,11.04 Sp F2V dist. 165.02 pc (538.3 l.y.)

STF1698 AB: 152; 125x: Near equal wide pair.  81% parallax range overlap, 1,519 AU weighted separation, 1.3+1.2 Msol, and the radial velocity delta 0.5 is less than the escape velocity 1.7.  It is likely binary and needs an orbit.

12h 54m 47.82s +74° 39' 06.1" P.A. 109.00 sep 10.1 mag 9.64,10.24 Sp A2

STF1767 AB: 152; 125x: Near equal well split pair.  52% parallax range overlap, 318 AU weighted separation, 1.0+1.0 Msol, it is probably binary.  SOC grade 5 orbit 3242-year period.

13h 34m 06.04s +67° 46' 07.9" P.A. 349.30 sep 4.5 mag 9.26,9.56 Sp G1V dist. 69.4 pc (226.38 l.y.)

STF1717 AB: 152; 125x: Very faint, very wide pair.  -52% overlap of the parallax ranges, it is not binary.

12h 28m 28.09s +88° 40' 32.4" P.A. 323.00 sep 8.3 mag 9.42,10.81 Sp F

 

STF1761 AB: 152; 125x: Near equal, wide, light orange stars.  No Gaia data on the primary.

13h 32m 01.67s +71° 43' 01.3" P.A. 71.00 sep 20.3 mag 9.30,10.10 Sp F8+F8 dist. 151.29 pc (493.51 l.y.)

STF1771 AB: 152; 200x: Narrowly split with 200x, 1 Dm, nice pair.  53% parallax range overlap, 194 AU weighted separation, 1.4+1.2 Msol.  Likely binary and needs an orbit.

13h 36m 41.90s +69° 46' 36.2" P.A. 83.00 sep 1.8 mag 8.77,9.37 Sp F5 dist. 98.14 pc (320.13 l.y.)

STF1798 AB: 152; 125x: 2 Dm, fairly wide.  24% parallax range overlap, 967 AU weighted separation, 1.9+1.2 Msol, and the radial velocity delta 2.0 is less than the escape velocity 2.4, it is likely binary and needs an orbit.

13h 55m 02.30s +78° 23' 59.2" P.A. 11.00 sep 7.5 mag 7.67,9.65 Sp F2 dist. 124.53 pc (406.22 l.y.)

STF1887 AB: 152; 125x: 1 Dm, fairly closely split.  -38% parallax range overlap, it is not binary.

13h 54m 57.46s +87° 23' 44.1" P.A. 227.00 sep 3.6 mag 9.18,11.20 Sp B9 dist. 176.99 pc (577.34 l.y.)