new scope

This past week I've had my new-to-me GSO 10" f/12 Classical Cassegrain set-up in my backyard.  Besides trying out the scope, it's also the first time to set-up the Losmandy G11 -- altogether a fairly steep learning curve.  

I plan to use this set-up in the generally good seeing at Fremont Peak to observe planets and double stars unavailable to me from home, those either too far south or to the north.  Reviews indicate the optical quality is good, and I should be able to reach the 0.5" Dawes limit.  I set-up the scope with my 80mm f/7 ED as the finder scope -- I wanted to have the occasion to use this scope for both wide field and to resolve brighter binaries.  The payload is 43 pounds, still within the weight limit of the mount -- though I found some shakiness and find I need to really tighten everything down.  I might switch from my portable pier to a tripod.  The stock focuser on the 10-inch is horrible -- very mushy -- and I've bought an adapter so I can use a Feathertouch I have instead (which should allow me to reach focus with binoviewers too).  I collimated the scope fairly well, but I need more practice with it.  I've struggled learning how to use the Gemini 2 on the mount, the instructions are not clear.  I have been able to align it and figure out how to start modeling it, but here too I need more practice.  The motors seem unusually loud, and might be annoying (since I'd be slewing every few minutes, unlike an astrophotographer who just tracks for hours at a time...).  I made a few observations with it so far, as below.

I have thought that a good refractor would be a better choice -- cleaner views when in average seeing -- but I'll stick with this set-up and see what results can be had when it's performing at its best.  I suppose I would only be going up the Peak when seeing would be forecasted to be excellent in any case, so the aperture problem should not be a dealstopper.

Also in other news, I finally took the Dalton objective up to Chabot to have R3 tested.  It is not spherical, rather an oblate spheroid.  

My thoughts are: If Dalton could not get the easiest of the Rx figures correct, there is high probability the other surfaces need even more work.  Given there is no local resource willing to help, and that I don't have the patience to try to refigure this myself, I plan to sell or give away the Dalton and will buy a ready-made objective--with a push-pull cell--instead.  I picked up a 9-foot aluminum tube yesterday which someone kindly offered to me -- it had been in their house for 50 years waiting for a refractor project which never materialized.  Since it's a shorter tube, I can build a scope around it with an f/12 objective, and even re-use the Dalton tailpiece (the tube is the same diameter as the Dalton).  If someone takes the Dalton objective, they can have the tube.  Once I find and buy a new objective I'll offer-up the Dalton.

STF 182 AB: 250; 170x: Slightly unequal, well split.  -12% PRO, it is not binary.

01h 56m 23.56s +61° 16' 52.0" P.A. 124.00 sep 3.6 mag 8.31,8.35 Sp B7V dist. 1754.39 pc (5722.82 l.y.)

STF 443 AB: 250; 170x: Light orange wide stars, 1 Dm.  -79% PRO, it is not binary, in spite of grade 4 SOC orbit.

03h 47m 02.11s +41° 25' 38.1" P.A. 57.00 sep 6.8 mag 8.20,8.82 Sp K2V+K3V dist. 21.91 pc (71.47 l.y.)

STF 446 AB: 250; 170x: 2 Dm, wide.  41% PRO, 9,536 AU WS, 6.8+3.5 Msol, it is possibly binary and needs an orbit.

03h 49m 27.57s +52° 39' 19.4" P.A. 254.00 sep 8.8 mag 6.86,9.90 Sp B0.5III dist. 1098.9 pc (3584.61 l.y.)

STF 448 AB: 250; 170x:  Very bright white A, well separated 3 Dm B.  -32% PRO, it is not binary.

03h 47m 52.66s +33° 35' 59.5" P.A. 13.00 sep 3.5 mag 6.68,9.36 Sp B2.5V dist. 325.73 pc (1062.53 l.y.)

STF 464 AB: 250; 170x: Bright white A, B was easy, well split.  56% PRO, 3,450 AU WS, 8.1+1.9, it is possibly binary and needs an orbit.  Slightly dimmer C and D further out. C shares similar parallax but does not overlap.  D is a widely varying parallax.

03h 54m 07.92s +31° 53' 01.2" P.A. 208.00 sep 12.8 mag 2.86,9.16 Sp B1Ib dist. 230.41 pc (751.6 l.y.)

STT  59 AB: 250; 170x: First observation made with the 10-inch CC.  Light orange stars, 1 Dm, well split.  52% PRO, 369 AU WS, 1.9+1.6 Msol, it is likely binary and needs an orbit.

03h 40m 40.62s +46° 01' 24.1" P.A. 355.00 sep 2.8 mag 7.90,8.85 Sp G5 dist. 111.36 pc (363.26 l.y.)

STT  66 AB: 250; 330x: Near equal white stars, good split.  92% PRO, 238 AU WS, 2.3+2.1 Msol, it is certainly binary.  SOC grade 4 orbit, 1198-year period.

03h 52m 04.69s +40° 47' 50.7" P.A. 146.00 sep 1.0 mag 8.11,8.54 Sp A2 dist. 236.41 pc (771.17 l.y.)

8 october 2024

A very productive couple of hours with the 6-inch.  Seeing was slightly better than average, and there was some marine haze, but still a nice night with some challenging pairs.  All from the CDSA list -- which unfortunately lacked accurate parallax data to reference, so many of them are not binary.

BU 391 AB: 152; 250x: Hairline split, near equal.  I can tell it's double at lower powers and even in the 60mm scope, lopsided shape at lower powers.  -5% PRO, 98 AU WS, 1.9+2.0 Msol, it is possible to be binary, SOC grade 4 orbit 575-year period, it won't make much appreciable change in PA or separation for the next 30 years.

00h 09m 21.02s -27° 59' 16.5" P.A. 258.00 sep 1.3 mag 6.13,6.24 Sp F4IV-V dist. 77.46 pc (252.67 l.y.)

FOX 127 AB: 152; 250x: The parent of BU 305 AC, bright white a, b seen rather closely separated with foveal coaxing, the can hold, best seen with higher powers.  No Gaia parallax data for the secondary.  BU 305 AC do not share parallax ranges, it is not binary.

02h 38m 17.86s +37° 43' 36.6" P.A. 270.00 sep 6.5 mag 6.16,11.30 Sp F5IV dist. 82.3 pc (268.46 l.y.)

HJ 1957 A-BC: 152; 125x: 1 Dm, well split.  -78% PRO, it is not binary.

00h 21m 52.40s -23° 00' 27.7" P.A. 27.00 sep 6.1 mag 7.67,9.15 Sp G0 dist. 59.49 pc (194.06 l.y.)

HJ 1991 AB: 152; 125x: 3 Dm wide.  -92% PRO, it is not binary.

00h 38m 48.78s -25° 06' 28.2" P.A. 95.00 sep 47.2 mag 6.58,9.73 Sp K0 dist. 273.97 pc (893.69 l.y.)

HJ 1992 AB: 152; 125x: 1 Dm, wide. -54% PRO, it is not binary. 

00h 38m 53.06s -25° 35' 44.9" P.A. 248.00 sep 45.8 mag 7.78,8.85 Sp A7V dist. 140.06 pc (456.88 l.y.)

HJ 2004 AB: 152; 125x: Closely split, 2 Dm.  23% PRO, 498 AU WS, 2.4+1.3 Msol, and RVD 2.0 < EV 3.6, it is likely binary and needs an orbit.

00h 57m 37.76s -18° 59' 55.0" P.A. 237.00 sep 3.3 mag 7.04,9.77 Sp A2Vn dist. 141.64 pc (462.03 l.y.)

MLF 1 AB: 152; 250x: B is quite faint, only with seeing, well split, very small compared to bright white A.  -89% PRO, it is not binary. Muller, F., who in 1889 published a paper with two discoveries.

00h 45m 41.71s -16° 25' 27.2" P.A. 197.00 sep 2.9 mag 6.54,10.41 Sp F2V dist. 89.05 pc (290.48 l.y.)

S 390 AB: 152; 125x: White near equal stars, well split.  Also seen with 60mm 40x.  41% PRO, 429 AU WS, 1.3+1.3 Msol, and RVD 0.1 < EV 3.3, it is likely binary and needs an orbit.

00h 58m 09.75s -15° 40' 58.0" P.A. 216.00 sep 6.5 mag 7.77,7.86 Sp dF6+dF7 dist. 59.45 pc (193.93 l.y.)

STF  12 AB: 152; 125x: White stars, 1 Dm, well split, also seen with 60mm 40x.  -17% PRO, it is not likely binary.

00h 14m 58.84s +08° 49' 15.5" P.A. 148.00 sep 11.2 mag 6.06,7.51 Sp A9V+F3V dist. 77.76 pc (253.65 l.y.)

STF  81 AB: 152; 125x: Wide B seen with averted vision then can hold.  91% PRO, 1,502 AU WS, 1.7+0.7 Msol, but RVD 3.3 > EV 1.7, it is not binary.

01h 00m 03.65s -02° 01' 08.1" P.A. 68.00 sep 18.0 mag 7.41,11.10 Sp F5 dist. 89.61 pc (292.31 l.y.)

STF  88 AB: 152; 125x: Clear light yellow-white equal stars, wide, also seen with 60mm 40x.  29% PRO, 2,704 AU WS, 2.8+2.5 Msol, it is possibly binary and needs an orbit.

01h 05m 40.93s +21° 28' 23.6" P.A. 159.00 sep 29.9 mag 5.27,5.45 Sp B9.5V+A0V dist. 84.32 pc (275.05 l.y.)

STF 133 AB: 152; 250x: Light orange A has a faint close companion, around 1" separation.  B is also a pair, well split, bluish color, easier to see high power.  AB only 1% PRO, 429 AU WS, 2.7+1.2 Msol, might not be binary.  CD -11% PRO, it is not binary either.  

AB: 01h 32m 47.71s +35° 50' 34.1" P.A. 191.00 sep 3.0 mag 6.79,9.44 Sp K3III dist. 136.24 pc (444.41 l.y.)

CD: 01h 32m 47.42s +35° 50' 14.8" P.A. 170.00 sep 5.1 mag 10.49,10.68

STF 141 AB: 152; 200x: Very closely split, near equal.  -10% PRO, it is not binary.

01h 40m 03.42s +38° 58' 10.7" P.A. 303.00 sep 1.7 mag 8.28,8.61 Sp F5 dist. 108.11 pc (352.65 l.y.)

STF 179 AB: 152; 125x: Near equal, closely split with low power. 10% PRO, 321 AU WS, 1.7+1.4 Msol, and RVD 0.6+4.1, it is likely binary and needs an orbit.

01h 53m 10.72s +37° 19' 16.3" P.A. 160.00 sep 3.5 mag 7.59,8.14 Sp F2V dist. 79.49 pc (259.3 l.y.)

STF 222 AB: 152; 125x: Easy, wide, bright near equal yellow-white stars.  21% PRO, 2,239 AU WS, 2.7+2.3 Msol, RVD 0.5 < EV 2.0, it is likely biary and needs an orbit.

02h 10m 52.83s +39° 02' 22.4" P.A. 36.00 sep 16.6 mag 6.05,6.71 Sp B9V+A1Vn dist. 139.66 pc (455.57 l.y.)

STF 245 AB: 152; 125x: Unequal wide pair.  89% PRO, 1,159 AU WS, 1.9+1.5 Msol, it is possibly binary and needs an orbit.

02h 18m 36.27s +40° 16' 43.7" P.A. 293.00 sep 11.3 mag 7.26,8.03 Sp F3V+F3V dist. 120.63 pc (393.5 l.y.)

STF2985 AB: 152; 125x: Light orange, slightly unequal wide stars.

STF2987 AB: 152; 200x: Light orange A, 3 Dm B, well split.  -29% PRO, it is not binary, despite the SOC grade 5 orbital solution.

23h 10m 21.28s +49° 01' 06.0" P.A. 149.00 sep 4.2 mag 7.42,10.41 Sp G1V dist. 45.39 pc (148.06 l.y.)

STF2992 AB: 152; 125x: Wide, 1 Dm white stars.  7% PRO, 2,716 AU WS, 2.3+1.5 Msol, but RVD 1.8 > EV 1.6, it is not binary.

23h 13m 06.32s +40° 00' 10.1" P.A. 285.00 sep 14.3 mag 7.66,9.59 Sp A3+F0 dist. 1666.67 pc (5436.68 l.y.)

STF3004 AB: 152; 125x: White stars, very unequal 4 Dm, well split.  -62% PRO, it is not binary.

23h 20m 44.10s +44° 06' 58.2" P.A. 177.00 sep 13.6 mag 6.26,10.13 Sp A5Vn dist. 75.24 pc (245.43 l.y.)

STF3042 AB: 152; 125x: Equal white stars, well split.  71% PRO, 390 AU WS, 1.4+1.4 Msol, it is likely binary and needs an orbit.

23h 51m 52.40s +37° 53' 28.4" P.A. 87.00 sep 5.9 mag 7.62,7.75 Sp F5V+A5 dist. 72.57 pc (236.72 l.y.)

STF3050 AB: 152; 200x: Near equal light yellow-white stars, split at 125x but better seen 200x.  63% PRO, 61 AU WS, 1.2+1.2 Msol, it is certainly binary.  SOC grade 3 orbit, 573-year period.

23h 59m 29.33s +33° 43' 26.9" P.A. 343.00 sep 2.6 mag 6.46,6.72 Sp F8V dist. 28.93 pc (94.37 l.y.)

STF3058 AB: 152; 125x: Wide, 1 Dm.  4% PRO, 1,899 AU WS, 2.0+1.4 Msol, RVD 1.5 < EV 1.8, it is possibly binary and needs an orbit.

00h 05m 09.24s +30° 19' 44.5" P.A. 51.00 sep 12.6 mag 7.81,9.21 Sp F3V+F6V dist. 253.16 pc (825.81 l.y.)

STF3061 AB: 152; 125x: Near equal white stars, well split.  -68% PRO, it is not binary.

00h 05m 44.45s +17° 50' 25.0" P.A. 149.00 sep 8.0 mag 8.40,8.51 Sp F5V+F5V dist. 128.04 pc (417.67 l.y.)

STN   3 AB: 152; 200x: Closely split, 1 Dm.  69% PRO, 102 AU WS, 1.2+1.0 Msol, it is likely binary and needs an orbit.  O. Stone, Cincinatti observatory.

00h 52m 12.81s -22° 37' 02.1" P.A. 240.00 sep 2.0 mag 7.63,8.39 Sp F8V dist. 52.97 pc (172.79 l.y.)

STT  18 AB: 152; 200x: Beautiful, 2 Dm, closely split with 125x, better seen 200x.  68% PRO, 128 AU WS, 1.4+0.9 Msol, it is possibly binary and needs an orbit.

00h 42m 23.21s +04° 10' 00.0" P.A. 211.00 sep 2.1 mag 7.86,9.71 Sp F8V dist. 59.99 pc (195.69 l.y.)

STT 501 AB: 152; 200x: Bright white A, B appears with foveal coaxing, well split. -26% PRO, it is not binary.

23h 40m 02.82s +37° 39' 09.5" P.A. 162.00 sep 15.0 mag 6.54,10.57 Sp F2IV dist. 90.83 pc (296.29 l.y.)

STT 513 AB: 152; 250x: White A and 3 Dm B, well split.  -34% PRO, it is not binary.

23h 58m 21.15s +35° 00' 46.8" P.A. 17.00 sep 3.7 mag 6.82,9.34 Sp A3 dist. 125.31 pc (408.76 l.y.)

WNO   1 AB: 152; 125x: 2 Dm, well split.  -6% PRO, it is not binary.

00h 53m 12.46s -24° 46' 37.0" P.A. 7.00 sep 5.4 mag 6.60,9.20 Sp F6IV-V dist. 73.58 pc (240.02 l.y.)

2 october 2024

Another good night on the 20-inch.  I started at 9:30pm after another hot day.  Worked the CDSA list for a while.  Seeing was predicted to be excellent after 11pm, but it didn't improve much -- but I was still pleased with the session, there were still many fine and challenging pairs to observe.

BAR 12 Ba-Bb: 508; 850x: Seeing not cooperating. Notched elongation, PA N-S line but I can't tell which is which. No Gaia data for the secondary.  SOC grade 4 orbit, 400-year period.

20h 20m 46.55s -14° 47' 05.5" P.A. 52.00 sep 0.4 mag 6.16,9.14 Sp A0III dist. 104.06 pc (339.44 l.y.)

BU 74 AB: 508; 420x: Excellent!  Very fine bluish B, nearly 2 Dm, very closely split.  Seen intermittently with lower magnification.  No Gaia parallax data for the secondary.

21h 35m 11.99s +21° 24' 14.9" P.A. 338.00 sep 1.0 mag 7.45,9.05 Sp F5V dist. 85.18 pc (277.86 l.y.)

BU 148 AB: 508; 500x: Light orange unequal stars, split, PA to the south.  No Gaia data.  SOC grade 5 orbit, 783-year period, if correct it will tighten for the next 40 years.

19h 52m 01.89s -10° 21' 13.5" P.A. 219.00 sep 0.6 mag 7.74,8.41 Sp F2 dist. 86.96 pc (283.66 l.y.)

BU 164 AB: 508; 1270x: Appears single, at periastron, splitable by 2040.  Burnham discovered at 0.64" with the 6-inch, and he predicted the period would be slow.  No Gaia data for the secondary.  SOC grade 4 orbit, 361-year period.

21h 25m 05.66s +09° 23' 02.6" P.A. 93.00 sep 0.1 mag 8.17,8.30 Sp A5IV-V dist. 136.05 pc (443.8 l.y.)

BU 681 AB: 508; 500x: Wow!  Extremely fine, light orange A pretty bright, B is just beyond A's first diffraction and very faint, a tiny white dot with seeing.  -47% PRO, it is not binary.

21h 13m 16.58s +16° 55' 08.4" P.A. 242.00 sep 2.9 mag 7.48,10.92 Sp K3III dist. 213.68 pc (697.02 l.y.)

COU 430 AB: 508; 635x: With seeing, PA to SW, very faint B well separated at this magnification.  No Gaia data for the secondary.

21h 25m 09.48s +18° 27' 45.4" P.A. 229.00 sep 0.8 mag 7.95,9.41 Sp A0 dist. 177.3 pc (578.35 l.y.)

HO 292 AB: 508; 195x: Faint B held with foveal coaxing, well split. -57% PRO, it is not binary.

22h 23m 15.11s +05° 38' 47.8" P.A. 64.00 sep 4.4 mag 7.66,11.24 Sp A2 dist. 141.04 pc (460.07 l.y.)

STF2658 AB: 178; 140x: White A and light orange B, well separated, 2 Dm.  89% PRO, 251 AU WS, 1.3+0.8 Msol, it is likely binary.  SOC grade 5 orbit, 5631-year period.

20h 13m 40.74s +53° 07' 30.3" P.A. 106.00 sep 5.2 mag 7.19,9.38 Sp F5V dist. 44.33 pc (144.6 l.y.)

STF2729 AB: 508; 635x: Split at 420x, best seen at 635x, light orange stars about 1 Dm, clean split.  No Gaia data on the secondary.  SOC grade 2 orbit, 200-year period -- 1 year shy of one full revolution since discovery!  

20h 51m 25.69s -05° 37' 35.9" P.A. 35.00 sep 0.7 mag 6.40,7.43 Sp F5IV-V dist. 60.72 pc (198.07 l.y.)

STF2786 AB: 178; 140x: White stars, well split, slightly unequal.  -27% PRO, it is not binary.

21h 19m 39.36s +09° 31' 30.3" P.A. 188.00 sep 2.8 mag 7.49,8.20 Sp A3IV dist. 185.53 pc (605.2 l.y.)

STF2797 AB: 178; 140x: Easy, well separated, > 1 Dm.  38% PRO, 624 AU WS, 2.4+1.7 Msol, and RVD 1.3 < EV 3.4, it is likely binary and needs an orbit tried.

21h 26m 41.14s +13° 41' 17.8" P.A. 218.00 sep 3.5 mag 7.37,8.83 Sp A2V dist. 221.73 pc (723.28 l.y.)

STF2799 AB: 178; 140x: Equal white stars, closely split.  -27% PRO, it is not binary.

21h 28m 52.79s +11° 05' 05.2" P.A. 259.00 sep 1.9 mag 7.37,7.44 Sp F4V dist. 105.04 pc (342.64 l.y.)

STF2809 AB: 178; 140x: 2 Dm very wide.  19% PRO, 3,508 AU WS, 2.4+1.2 Msol, but RVD 2.7 > EV 1.4, it is not binary.

21h 37m 33.76s -00° 23' 26.0" P.A. 163.00 sep 31.1 mag 6.22,9.36 Sp A2III+F5V dist. 112.87 pc (368.18 l.y.)

STF2854 AB: 178; 200x: Near equal dull white, close split.  45% PRO, 130 AU WS, 1.4+1.4 Msol, it is likely binary and needs an orbit.

22h 04m 22.52s +13° 38' 53.4" P.A. 84.00 sep 1.6 mag 7.77,7.89 Sp F6V dist. 72.1 pc (235.19 l.y.)

STF2878 AB: 178; 200x: Lovely close split, 2 Dm.  -53% PRO, it is not binary.

22h 14m 29.18s +07° 58' 34.2" P.A. 116.00 sep 1.6 mag 6.94,8.11 Sp B9IV dist. 224.22 pc (731.41 l.y.)

STFA 56 AB: 178; 140x: Super-wide, nearly 2 Dm.  -83% PRO, it is not binary.

21h 37m 43.64s +06° 37' 06.2" P.A. 349.00 sep 38.7 mag 6.18,7.50 Sp A2V dist. 145.35 pc (474.13 l.y.)

STFB 11 AB: 178; 140x: Bright white A and wide 2 Dm B. -82% PRO, it is not binary.

21h 22m 05.13s +19° 48' 15.7" P.A. 313.00 sep 36.6 mag 4.20,9.30 Sp K1III+K0V dist. 47.78 pc (155.86 l.y.)

STTA222 AB: 178; 140x: 1 Dm, super-wide.  51% PRO, 8,370 AU WS, 1.7+1.4 Msol, but RVD 0.9 > EV 0.8, and the fact the weighted separation is >5,000 AU, it is not likely binary.

21h 44m 07.92s +07° 09' 29.7" P.A. 258.00 sep 87.4 mag 7.49,8.47 Sp F2V

1 october 2024 movement pairs

Seeing was pretty good last night, good enough to chase after some movement pairs.  A lot of extremely close ones which are not quite resolved.  There's a large heat dome over our area, so the good seeing will continue the next couple of days.  The solar viewing has been quite good -- I've been able to use full 6-inch aperture with my Ha set-up, and the views are outstanding.

A 95 AB: 508; 1000x: Light orange stars, in moments of best seeing there is a hairline split, notched elongation otherwise.  Unequal, PA to SW.  SOC grade 2 orbit, 108.72-year period, it will close rapidly over the next decade.  Seems I observed it just in time...

19h 11m 01.26s -07° 25' 38.7" P.A. 20.00 sep 0.2 mag 7.40,7.95 Sp F8V dist. 173.61 pc (566.32 l.y.)

A 1658 AN: 508; 1270x: Out-of-round olive, weaker side to NE.  SOC grade 2 orbit, 88.1-year period, it has a nearly circular orbit and will be at 0.24" in the mid-2030s, should be resolvable then.  

19h 48m 39.64s +15° 03' 32.4" P.A. 54.00 sep 0.2 mag 8.30,8.74 Sp F5V dist. 136.61 pc (445.62 l.y.)

HO 276 AB: 508; 850x: Light yellow star with a slight bump to the SW.  No orbit diagram or ephemeris provided in SOC, nor in the source paper...

19h 59m 47.49s -09° 57' 26.2" P.A. 109.00 sep 0.2 mag 6.22,7.83 Sp F8V dist. 22.2 pc (72.42 l.y.)

KUI  93 AB: 508; 850x: Brilliant white, elongated N-S but can't tell which is weaker.  SOC grade 3 orbit, 65-year period, it will widen (but too slowly for me to resolve it) to periastron in 2050 at 0.179"

19h 41m 05.53s +13° 48' 56.5" P.A. 317.00 sep 0.1 mag 6.69,6.75 Sp B5V+A8IV dist. 2040.82 pc (6657.15 l.y.)

STF2534 AB: 178; 140x: Equal white stars, well separated.  -36% PRO, they are not binary.

19h 27m 40.63s +36° 31' 44.4" P.A. 63.00 sep 7.0 mag 8.21,8.39 Sp B9III dist. 900.9 pc (2938.74 l.y.)

STT 373 AB: 178; 200x: Very fine, 2 Dm, close separation.  85% PRO, 490 AU WS, 2.7+1.6 Msol, it is very likely binary and needs an orbit. 

19h 24m 05.52s +46° 26' 18.3" P.A. 232.00 sep 1.8 mag 7.63,9.93 Sp B9.5II dist. 277.01 pc (903.61 l.y.)

STT 383 AB: 178; 420x: Exceptionally fine, 1 Dm white and blue, just split, B sits within A's first diffraction ring, needed higher power to push the two apart. SOC grade 4 orbit, 1125-year period, 51% PRO, 171 AU WS, 2.7+2.1 Msol, it is binary. 

19h 42m 56.26s +40° 43' 18.3" P.A. 15.00 sep 0.8 mag 7.03,8.28 Sp B9.5V dist. 154.56 pc (504.17 l.y.)

STT 432 AB: 178; 200x: Slightly unequal white stars, just split at 140x, better seen 200x.  -71% PRO, it is not binary.

21h 14m 18.94s +41° 08' 48.0" P.A. 115.00 sep 1.3 mag 7.78,8.05 Sp F8V dist. 244.5 pc (797.56 l.y.)

STT 434 AB: 178; 140x: Brighter white, 2 Dm, wide.  No Gaia parallax data for the secondary.

21h 19m 00.03s +39° 44' 57.6" P.A. 122.00 sep 24.4 mag 6.67,9.93 Sp B9V dist. 143.88 pc (469.34 l.y.)

STT 365 AB; 508; 1270x: Light yellow stars, overlapping disks, slightly unequal, PA is N.  No SOC orbit.

18h 55m 57.14s +44° 13' 41.9" P.A. 359.00 sep 0.2 mag 7.20,8.30 Sp A2 dist. 186.57 pc (608.59 l.y.)

WCK 2 Aa-Ab: 508; 1270x: Olive, weak side PA SW, all powers, blue filter.  SOC grade 2 orbit, 17-year period, it is near apastron now in its slightly elliptical orbit and will widen by a hundredth of an arcsecond in 2026.  Also saw BU 298 AB, 3.86/13.40, 35.5", as the very faint and small B widely separated with the high magnification.  

20h 39m 38.25s +15° 54' 43.4" P.A. 289.00 sep 0.1 mag 3.86,6.43 Sp B9IV dist. 77.82 pc (253.85 l.y.)

disappointing night

I went observing at the dark site along the central coast last night.  Overall a frustrating night observing-wise.  I couldn't decide what I wanted to observe, nebula or galaxies, so I split the difference and packed my NP101 and C8.  But my mount's encoders were on the fritz, and I couldn't use the DSC -- with as narrow a field as the C8 has, and no RACI to help star hopping, I was a bit lost.  I spent most of the time on the NP101 revisiting previously observed objects.  While the forecast was for excellent transparancy, I knew from the satellite there was upper level moisture coming overhead.  But the effect of it was worse than I expected.  My SQML never got above 21.0.  No dew, fortunately.

Coyotes howling and yapping pretty close, I felt nervous, though I'm usually able to ignore it.  Heard a wildcat snarl? roar? in the early part of the night.

Late I heard a sound like someone shaking out a towel behind me, it must have been its wings.  A few seconds later a large owl flew over my head about 10' up. 

One really great observation was watching the Eagle Nebula set behind the rocky prontmontory of a nearby ridge.  The Pillars going first.  All that dust and gas in the nebula, in front of solidified dust and gas...makes one think of the large scales of time in the universe.  I imagine the rocks on the ridge are old, but the dust is older...  Once it started setting it moved very fast, a matter of moments and it was gone.

My only useful observation, some nebulae north of the Veil near Epsilon Cyg, about as faint as the weak nebula next to Flemming's Triangle, which was on the edge of the field.  Still trying to identify it.

I felt tired by 12:30pm and wrapped up.  Slept in fits but felt ok in the morning.  Woke at 5:30am, still dark, and got out of the car to watch a thin cresent moon with luminous earthshine rise above the eastern ridge.  The sky was still clear and sparkling with the bright winter constellations, Orion and Canis Major culminating.  Remembered comet C/2023 A3 (Tsuchinshan-ATLAS) is very low in the brightening morning sky, so I started driving (I packed everything the night before) east to find a clearning for a better view.  Unfortunatley the clearest opening had a low ridge in the way, though the moon was still pretty.  I got out and ate a roll and some yogurt for my breakfast, watching the sky in case I could see the comet.  I could not.  But, refreshed, I continued on the drive home.

27 september 2024, movement pairs

Observed with my 20-inch.  Good transparency and better than expected seeing, so I went after pairs on my "movement" list, with very good results.  Once it cleared the meridian tree I had a nice view of Saturn.  All with apodising screen.

 A 1238 AB: 508; 1270x: Very difficult, need moments of best seeing, unequal pair, barely split, PE to the NE.  SOC grade 2 orbit, and unfortunately it will remain a very difficult pair through its turn N to W through 2040.

23h 08m 47.77s +10° 57' 31.1" P.A. 70.00 sep 0.2 mag 8.20,8.79 Sp F6V dist. 119.19 pc (388.8 l.y.)

AGC  13 AB: 508; 400x: Using an apodising screen and a blue filter, the secondary was clear and steady in light diffraction, nicely separated from the primary, PA SSE, best seen at 400x.  I also put on a 7-inch off-axis mask (effective f/14.3), still at 400x and with the blue filter.  The star image was greatly cleaned-up, with one faint diffraction ring.  B was dimmer but I could still hold it easily.  SOC grade 2 orbit, 49.52-year period, it will be due east by 2034 and a very difficult 0.5".

21h 14m 47.49s +38° 02' 43.1" P.A. 190.00 sep 1.1 mag 3.83,6.57 Sp F3V+F7V dist. 20.34 pc (66.35 l.y.)

BU 1212 AB: 508; 1270x: Unequal, PA SSW, light yellow, hairline at best moments.  SOC grade 2 orbit, 48.65-year period, it will gradually widen to the west and be an easy 0.5" by 2042.  Burnham says in his GC: "Discovered with the 36-inch.  It was evident at the time of discovery [1890.75, 0.45" 254.5-degrees or WSW] the close pair was a binary from the common proper motion of the components, as otherwise the duplicity would have been seen long ago [I suspect it was too close for most observers to see or measure, such as STT]....The motion of AB is slow so far, but it is probable that the components have about the maximum separation at this time, and that hereafter the angular motion will be more rapid [he was essentially correct on this point!].

21h 39m 31.39s -00° 03' 04.1" P.A. 156.00 sep 0.1 mag 6.94,8.44 Sp F6V dist. 43.98 pc (143.46 l.y.)

KUI 108 AB: 508; 1270x: Light orange stars, out of round only, unequal PA to N.  SkyTools says the period is 26.5-years, and SOC offers this orbital solution, showing the pair at apastron now.

21h 42m 22.94s +41° 04' 37.3" P.A. 14.00 sep 0.2 mag 6.33,6.72 Sp A0V dist. 126.42 pc (412.38 l.y.)

KUI 114 AB: 508; 1270x: Light orange star, out of round or olive shaped, PA SE.  SOC grade 2 orbit, which is nearly edge-on, 54.57-year period, the pair will soon dive back to periastron soon, emerging and detectable on the opposite PA in the mid-2040s.

22h 40m 47.97s -03° 33' 15.4" P.A. 129.00 sep 0.35 mag 6.52,8.63 Sp F6V dist. 34.57 pc (112.77 l.y.)

STT 535 AB: 508; 1270x: Using an apodising mask and blue filter, at >500x the elongation was obvious, and bumping the magnification up to 1270x I had a clean split, slightly unequal stars with PA to the NE.  Spurious disks were fairly steady but there was a fair amount of dancing diffraction at this magnification.  I observed it in October 2020 with the 20-inch, when it was at 0.165", and it appeared single.  So this makes a handful of pairs in which I've been able to trace movement over the last few years.  We have another four years or so before the secondary makes its dive back toward the primary and will be undetectable visually.  What a fun observation, 5.71-year period!  SOC grade 1 orbit.

21h 14m 28.81s +10° 00' 25.1" P.A. 7.00 sep 0.33" mag 5.19,5.52 Sp F6V+F6V dist. 18.49 pc (60.31 l.y.)

22 september 2024

Seeing was predicted to be good, but I felt tired from a busy day so I only uncovered the 6-inch to observe.  I wanted to try a difficult double someone posted about on CN, so I spent most of my time on it:

AGC 13 AB: 152; 450x: Holy heck is it a tough one!  I had airy disks well above 300x, and what makes this tough is the secondary is hidden in the first diffraction ring.  The ring would sometimes pulse, if that's the word, with small bright globs coursing around the ring with seeing.  But the southern end was constant in its brightness, and with best seeing (and perfect focus) at 380x & 450x it hardened to a round steady star, separated, almost exactly south.  The view was improved by viewing the star through a peephole (a 1/32" hole I drilled in the center of the eyepiece's dust cap) which helps to steady the seeing a little--this is one of SW Burnham's observing tricks.  Through the peephole I could hold the secondary for longer stretches.  SOC grade 2 orbit, 49.52-year period, it will tighten in the next 10 years and turn due east, but not likely be visible.  No Gaia parallax data.

21h 14m 47.49s +38° 02' 43.1" P.A. 190.00 sep 1.1 mag 3.83,6.57 Sp F3V+F7V dist. 20.34 pc (66.35 l.y.)

STF2523 AB: 152; 125x: Clean white equal stars, also seen with 60mm at 40x. -4% PRO, 3,303 AU WS, 3.5+3.3 Msol, it is not likely binary.

19h 26m 48.38s +21° 09' 46.2" P.A. 148.00 sep 6.4 mag 7.95,8.05 Sp B3V+B7V dist. 1470.59 pc (4797.06 l.y.)