12 april 2023

Spent a night out with the 6-inch refractor, and spent a pleasant evening scooping up Struves, mostly in the far northern latitudes where the 20-inch is blocked from seeing.  It was a bit hazy and seeing was only average, but a good haul all the same.

STF1169 AB: 152; 125x: Wide, >1 Dm.  SOC has a grade 5 orbit, but there is no parallax range overlap, -15%, it is not binary.  

08h 16m 31.05s +79° 30' 03.5" P.A. 15.00 sep 20.6 mag 8.40,8.64 Sp G0 dist. 45 pc (146.79 l.y.)

STF1523 AB: 152; 125x: Hairline split, 1 Dm, nice. Alula australis.  SOC grade 1 orbit 59.98-year orbit, it will make a quarter turn from SSE to E by 2045, widening slightly.

11h 18m 10.90s +31° 31' 45.0" P.A. 148.80 sep 2.2 mag 4.33,4.80 Sp F9V+G9V dist. 10.42 pc (33.99 l.y.)

STF1576 AB: 152; 125x: Nearly 1 Dm, well split.  There is 50% parallax range overlap, 833 AU weighted separation, 1.5+1.4 Msol, so it might be binary and an orbit should be tried.

11h 52m 52.60s +30° 49' 38.4" P.A. 241.00 sep 5.3 mag 9.11,9.45 Sp F5 dist. 163.67 pc (533.89 l.y.)

STF1583 AB: 152; 125x: 1 Dm, pretty wide.  87% overlap of the parallax ranges, 2,453 AU weighted separation, 2.2+1.7 Msol, likely binary and an orbit should be tried.

12h 00m 10.43s +86° 59' 40.0" P.A. 284.00 sep 11.3 mag 8.10,9.29 Sp A2V dist. 289.02 pc (942.78 l.y.)

STF1625 AB: 152; 125x: White, slightly unequal stars, wide.  Also seen with 60mm telescope.  19% overlap of the parallax ranges, 1,232 AU weighted separation, 1.7+1.5 Msol, and the radial velocity delta 0.5 is less than the escape velocity 2.2, it is likely binary and needs an orbit

12h 16m 11.66s +80° 07' 30.3" P.A. 217.00 sep 14.5 mag 7.24,7.78 Sp F1V+F3V dist. 497.51 pc (1622.88 l.y.)

STF1694 AB: 152; 125x: White near equal stars, wide, also seen with 60mm scope.  -6% parallax range overlap, it is not likely binary.

12h 49m 13.80s +83° 24' 46.3" P.A. 324.00 sep 21.8 mag 5.29,5.74 Sp A1IIIsh dist. 178.89 pc (583.54 l.y.)

STF1720 AB: 152; 200x: Split with seeing, near equal stars.  6% parallax range overlap, 590 AU weighted separation, 2.3+2.2 Msol, it is possibly binary and an orbit should be tried.

12h 59m 12.92s +82° 56' 05.4" P.A. 329.00 sep 1.7 mag 8.91,9.18 Sp A0

STF1745 AB: 152; 125x: B appears with averted vision only, white.   -94% parallax range overlap, it is not binary.  

13h 20m 17.23s +79° 26' 13.1" P.A. 182.00 sep 19.3 mag 8.92,11.60 Sp G5

STF1787 AB: 152; 150x: B with averted vision only, tough, closely split.  -12% parallax range overlap, it is not binary.

13h 40m 38.33s +81° 10' 51.0" P.A. 335.00 sep 2.0 mag 9.59,11.00 Sp F8 dist. 448.43 pc (1462.78 l.y.)

STF1822 AB: 152; 125x: Significant delta, wide, faint B brightens with averted vision.  -93% parallax range overlap, it is not binary.

14h 09m 37.57s +72° 50' 04.3" P.A. 52.00 sep 15.0 mag 9.15,10.80 Sp K2

STF1836 AB: 152; 125x: Wide, significant delta.  -47% parallax range overlap, it is not binary.

14h 17m 48.71s +69° 18' 49.2" P.A. 110.00 sep 21.6 mag 10.74,11.25 Sp G0+F4

STF1840 AB: 152; 125x: Wide, significant delta.  -20% parallax range overlap, it is not binary.

14h 19m 54.86s +67° 46' 56.9" P.A. 221.00 sep 27.2 mag 6.95,10.05 Sp B9V dist. 142.65 pc (465.32 l.y.)

STF1841 AB: 152; 125x: Wide, very faint, need averted vision to draw them out, then can barely hold them direct vision.  -67% parallax range overlap, it is not binary.

14h 21m 07.78s +67° 48' 10.4" P.A. 264.00 sep 35.0 mag 7.32,11.07 Sp A2 dist. 164.2 pc (535.62 l.y.)

STF1844 AB: 152; 200x: A bump or snowman from the main star, very faint, very tough, with seeing.  73% parallax range overlap, only 302 AU weighted separation, 1.3+1.0 Msol, it is likely binary and needs an orbit.

14h 17m 43.93s +76° 47' 46.8" P.A. 209.00 sep 1.9 mag 9.77,10.89 Sp G5 dist. 194.17 pc (633.38 l.y.)

STF1849 AB: 152; 200x: B seen with averted and brightens next to the primary star, barely split.  24% parallax range overlap, 137 AU weighted separation, 1.3+1.2 Msol, it is possibly binary and needs an orbit. 

14h 19m 49.36s +76° 42' 02.4" P.A. 10.00 sep 0.9 mag 9.70,10.09 Sp F5 dist. 146.63 pc (478.31 l.y.)

STF1851 AB: 152; 125x: Very faint, just barely seen with direct vision, well split, significant delta magnitude.  -46% parallax range overlap, it is not binary.

14h 17m 11.18s +79° 51' 38.0" P.A. 329.00 sep 10.5 mag 9.78,12.30 Sp F8

STF1859 AB: 152; 125x: Near equal wide pair.  -21% parallax range overlap, it is not binary.

14h 28m 31.85s +73° 03' 18.3" P.A. 234.00 sep 19.9 mag 8.63,10.12 Sp A2 dist. 2857.14 pc (9319.99 l.y.)

STF1880 AB: 152; 125x: Very faint B seen with averted vision, wide.  -83% parallax range overlap, it is not binary.

14h 33m 15.18s +79° 46' 26.4" P.A. 254.00 sep 26.1 mag 10.42,11.73

STF1897 AB: 152; 125x: Wide near equal pair.  -65% parallax range overlap, it is not binary.

14h 53m 35.35s +69° 45' 46.1" P.A. 319.00 sep 35.9 mag 7.61,10.99 Sp K5 dist. 636.94 pc (2077.7 l.y.)

STF1905 AB: 152; 200x: Near equal, nice close split.  77% parallax range overlap, only 218 AU weighted separation, 1.1+1.1 Msol, it is possibly binary and needs an orbit.

14h 56m 47.88s +70° 49' 58.5" P.A. 163.00 sep 3.0 mag 9.05,9.43 Sp F8 dist. 58.62 pc (191.22 l.y.)

STF1906 AB: 152; 125x: Near equal wide.  -91% parallax range overlap, it is not binary.

14h 58m 21.74s +71° 08' 26.8" P.A. 204.00 sep 17.0 mag 8.48,10.18 Sp F5

STF1915 AB: 152; 200x: Nearly one delta, very closely split.  -74% parallax range overlap, it is not binary.

14h 33m 17.54s +85° 56' 18.4" P.A. 319.00 sep 2.4 mag 7.33,9.69 Sp K0 dist. 179.53 pc (585.63 l.y.)

STF1928 AB: 152; 125x: Near equal, well split.  -6% parallax range overlap, it is not binary.

15h 09m 17.20s +72° 27' 16.4" P.A. 275.00 sep 6.5 mag 9.56,10.24 Sp G5

STF1933 AB: 152; 125x: 1 Dm, wide B seen with averted vision only.  5% parallax range overlap, 4,338 AU weighted separation, 1.5+0.9 Msol, but the radial velocity delta 2.3 far exceeds the escape velocity 1.0, it is not binary.

15h 05m 14.43s +79° 03' 34.1" P.A. 276.00 sep 24.2 mag 9.43,11.75 Sp G0 dist. 143.88 pc (469.34 l.y.)

STF1958 AB: 152; 125x: Near equal wide pair.  24% parallax range overlap, 6,188 AU weighted separation, 1.5+1.4 Msol, so there is some possibility it is binary and an orbit should be tried. 

15h 29m 24.12s +67° 12' 16.0" P.A. 337.00 sep 29.6 mag 9.63,9.97 Sp G5

STF1971 AB: 152; 125x: Wide faint B seen with averted vision.  -97% parallax range overlap, it is not binary.

15h 35m 12.91s +75° 20' 16.4" P.A. 317.00 sep 15.0 mag 9.64,11.99 Sp K5

STF1972 AB: 152; 125x: Near equal, wide, easy.  -11% parallax range overlap, it is not binary.

15h 29m 11.19s +80° 26' 55.0" P.A. 80.00 sep 31.6 mag 6.64,7.30 Sp G0IV-V dist. 21.85 pc (71.27 l.y.)

STF1980 AB: 152; 125x: Easy near equal pair.  -74% parallax range overlap, it is not binary.

15h 32m 27.04s +81° 03' 10.4" P.A. 49.00 sep 10.1 mag 9.15,9.52 Sp F0

STF1989 AB: 152; 200x: Very strongly notched elongation, hairline split at best seeing moments.  No Gaia data for the secondary, SOC gives a grade 3 orbit 171.62-year period, it will close somewhat by 2040.

15h 39m 38.61s +79° 58' 59.6" P.A. 20.90 sep 0.6 mag 7.32,8.15 Sp F2V dist. 120.05 pc (391.6 l.y.)

STF1997 AB: 152; 125x: 1 Dm, wide, B with averted vision only.  -95% parallax range overlap, it is not binary.

15h 47m 52.79s +77° 46' 08.8" P.A. 339.00 sep 18.3 mag 9.31,12.16 Sp K0

STF2002 AB: 152; 125x: Nearly 1 Dm, wide.  -92% parallax range overlap, it is not binary.

15h 47m 36.09s +83° 16' 25.7" P.A. 314.00 sep 42.5 mag 8.81,10.61 Sp F5

STF2013 AB: 152; 125x: Wide, nearly 1 Dm, B brightens with averted vision.  -96% parallax range overlap, it is not binary.

15h 57m 14.53s +76° 28' 44.3" P.A. 274.00 sep 20.6 mag 10.02,11.01 Sp K0

STF2020 AB: 152; 150x: Wide faint B seen with averted vision only.  -96% parallax range overlap, it is not binary.

16h 00m 00.11s +76° 15' 22.7" P.A. 244.00 sep 26.6 mag 9.86,10.80 Sp G5

STF2034 AB: 152; 200x: Split with seeing, equal magnitude.  11% parallax range overlap, 338 AU weighted separation, 2.7+3.1 Msol, so it might be binary and an orbit should be tried.

15h 48m 43.02s +83° 37' 10.5" P.A. 110.00 sep 1.1 mag 7.68,7.95 Sp A3 dist. 381.68 pc (1245.04 l.y.)

20 april 2023

Observed with the 20-inch but masked down to 7-inches for most of the night due to seeing.  I was able to go after a couple of challenge movement pairs at the end of the night.  Average transparency.

STF1559 AB; 178; 140x: Pretty white stars, 1 Dm, close but comfortably split.  There is no parallax range overlap, -49%, it is not binary. 

11h 38m 49.11s +64° 20' 49.4" P.A. 326.00 sep 2.0 mag 6.81,8.01 Sp A5IV dist. 210.97 pc (688.18 l.y.)

 

STF1567 AB; 178; 140x: >2 Dm, pretty close around 2" separation.  There is 31% parallax range overlap, only 824 AU weighted separation, 1.7+1.3 Msol, so it is possibly binary and needs an orbit.

11h 42m 58.94s +64° 21' 19.4" P.A. 84.00 sep 3.6 mag 9.35,10.50 Sp F5

STF1407 AB: 178; 140x: Faint near equal pair, well split.  There is 40% overlap of the parallax ranges, 857 AU weighted separation, 1.3+1.1 Msol, and the radial velocity delta -0.4 is less than the escape velocity 2.2, an orbit should be tried.

10h 09m 01.98s +64° 26' 40.6" P.A. 51.00 sep 4.9 mag 10.17,10.63 Sp K7 dist. 176.06 pc (574.31 l.y.)

STF1398 AB: 178; 140x: White and significantly fainter 3 Dm B, pretty closely split.  There is no parallax range overlap, -96%, it is not binary.

10h 01m 32.06s +68° 43' 05.1" P.A. 102.00 sep 4.1 mag 8.09,11.39 Sp F0 dist. 159.24 pc (519.44 l.y.)

STF1400 AB: 178; 140x: In same filed as STF1398, faint pair, pretty closely split.  There is 76% overlap of the parallax ranges, only 243 AU weighted separation, 1.3+0.8 Msol, and the radial velocity delta 1.9 is less than the escape velocity 3.9.  It is likely binary and needs an orbit.

10h 02m 56.49s +68° 47' 09.3" P.A. 225.00 sep 3.6 mag 8.02,9.77 Sp F5 dist. 61.73 pc (201.36 l.y.)

STF1415 AB: 178; 140x: AB is a pretty 1Dm pair of bright stars, very light yellow A and light blue B.  C is one of the widely separated faint stars in the field.   AB has 75% parallax range overlap, 2,024 AU weighted separation, 2.3+2.0 Msol, and the radial velocity delta 0.8 is less than the escape velocity 1.9, it is likely binary and needs an orbit.  

10h 17m 50.61s +71° 03' 38.9" P.A. 168.00 sep 16.5 mag 6.65,7.27 Sp A7m+Am dist. 401.61 pc (1310.05 l.y.)

STF1508 BC: 178; 140x: Faint trio of near equal stars, though one is fainter needed 200x to see plainly.  BC is actually has the closest separation, AB and AC were measured originally but I don't know why because they are very wide.  There is 3% parallax range overlap, though with 3% error, 3,372 AU weighted separation, 1.4+1.3 Msol, and the radial velocity delta 0.4 is less than the escape velocity 1.2.  Marginal to be binary, but an orbit should be tried in any case.

11h 08m 33.82s +68° 24' 40.4" P.A. 243.00 sep 8.6 mag 10.41,10.86

STF1418 = HJ 3324 AB: Faint pair, <1Dm, well split.  There is 18% parallax range overlap, 6,057 AU weighted separation, 1.8+1.4 Msol, but the radial velocity delta 1.8 exceeds the escape velocity 1.0, so it is not likely binary. 

10h 20m 23.83s +68° 08' 20.3" P.A. 199.00 sep 18.6 mag 9.95,11.04 Sp K2 dist. 183.82 pc (599.62 l.y.)

STF1498 AC: 178; 140x: BU 1430 AB is >1 Dm, wide, B brightens with averted vision.  AC is a wide pair, surprising Struve missed AB.  Surprisingly, there is no parallax overlap for AB -80%.  AC has 8% parallax range overlap, but a wide 7,751 AU weighted separation, 2.7+1.2 Msol, but the radial velocity delta 2.9 far exceeds the escape velocity 0.9, so it likely is not binary either.

11h 01m 35.83s +66° 26' 59.1" P.A. 13.00 sep 8.6 mag 7.95,11.41 Sp K0 dist. 320.51 pc (1045.5 l.y.)

STF1514 AB: 178; 280x: Nice close pair, faint need higher power to get a nice split, 1 Dm.  10% parallax range overlap, 367 AU weighted separation, 1.9+1.4 Msol, so there is some chance it is binary and an orbit should be tried. 

11h 11m 38.55s +66° 06' 48.0" P.A. 342.00 sep 1.3 mag 9.49,10.64 Sp F2

STF1469 AB: 178; 140x: >1 Dm, wide.  74% parallax range overlap, 892 AU weighted separation, 1.5+0.8 Msol, but the radial velocity delta 2.4 is slightly more than the escape velocity 2.2.  There is a slight chance it is binary and an orbit should be tried.

10h 47m 43.86s +65° 27' 36.4" P.A. 324.00 sep 10.9 mag 7.74,10.42 Sp F8V dist. 86.88 pc (283.4 l.y.)

STF1550 AB: 178; 140x: 1 Dm, wide.  There is no parallax range overlap, -97%, it is not binary.

11h 34m 39.80s +63° 38' 35.9" P.A. 41.00 sep 18.1 mag 8.93,11.13 Sp G0 dist. 68.12 pc (222.21 l.y.)

STF1444 AB: 178; 140x: GT UMa.  >1Dm, wide.  77% parallax range overlap, 3,488 AU weighted separation, 2.2+1.1 Msol, but the radial velocity delta 10.2 far exceeds the escape velocity 1.3, it is not likely binary.

10h 35m 55.66s +63° 35' 32.4" P.A. 266.00 sep 17.9 mag 8.17,10.72 Sp F2 dist. 145.77 pc (475.5 l.y.)

STF1513 = H 4 106 AB: 178; 280x: Faint B needed high magnification to see, well split.  There is -22% parallax range overlap, it is not binary. 

11h 09m 45.09s +63° 20' 06.5" P.A. 133.00 sep 20.3 mag 7.97,10.88 Sp F7V dist. 88.11 pc (287.41 l.y.)

STF1505 AB: 178; 140x: 1 Dm, well split.  There is no parallax range overlap, -47%, it is not binary.

11h 05m 41.23s +62° 37' 01.5" P.A. 312.00 sep 8.2 mag 8.95,10.55 Sp G5 dist. 185.53 pc (605.2 l.y.)

STF1512 AB: 178; 140x: Equal white stars, well split.  Thiere is no parallax range overlap, -86%, it is not binary.

11h 09m 13.09s +62° 29' 51.0" P.A. 51.00 sep 9.9 mag 9.29,9.52 Sp A2 dist. 448.43 pc (1462.78 l.y.)

STF1491 AB: 178; 140x: Faint B seen with averted vision, then can hold direct, well split.  There is 57% overlap of the parallax ranges, 4,287 AU weighted separation, 2.7+1.2 Msol, but the radial velocity delta 3.8 exceeds the escape velocity 1.3, it is not likely binary.

10h 58m 50.42s +61° 42' 56.4" P.A. 33.00 sep 14.1 mag 8.39,11.33 Sp K0 dist. 1052.63 pc (3433.68 l.y.)

STF1519 AB: 178; 200x: Lovely pair, half delta mag, split at 140x but better at 200x, close, a bit more than 1" separation.  There is 53% parallax range overlap, 306 AU weighted separation, 1.8+1.4 Msol, so it is likely binary and an orbit should be tried.  

11h 15m 36.65s +59° 46' 43.4" P.A. 289.00 sep 1.5 mag 9.03,9.95 Sp F5 dist. 250.63 pc (817.56 l.y.)

STF1545=STF1544 AB: 178; 140x: Near equal bright white stars, wide.  There is no parallax range overlap, -65%, 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.)

HU 462 AB: 508; 850x: Hairline split, N-S PA, significant delta, two other stars in view to mark the position.  No parallax data.  SOC grade 2 orbit, 48.4-years, it is currently NNE and has a nearly circular orbit, will make a quarter turn clockwise to the W by 2040.

11h 27m 10.78s -15° 38' 55.0" P.A. 36.80 sep 0.4 mag 8.42,8.53 Sp G8V dist. 35.95 pc (117.27 l.y.)

HDS1572 AB: 508; 850x: Very slightly notched elongation, SSE PA.  SOC grade 3 orbit, 18.45-years, it reaches apastron in 2025, then closes rapidly in the early 2030s, to be seen again 2040.  No Gaia data for the secondary.

11h 01m 23.29s -12° 03' 34.1" P.A. 153.30 sep 0.2 mag 8.27,9.87 Sp G5 dist. 46.36 pc (151.23 l.y.)

clouds of gas, dust, and pollen

I went observing last Saturday night at a site in San Benito county.  It was the best forecasted night for the new moon cycle, though upper level transparency was still to be a problem.  I was headed to Pinnacles, in Morgan Hill buying food, when I saw an email from Akarsh asking if anyone was headed out to the site.  I texted and called him and we firmed up our plans.  I was happy to have somewhere else to observe, since Pinnacles is getting very busy, and there is some uncertainty about whether observers are welcome on the west side anymore.

I drove down Panoche Road, remembering all the times I went to Willow Springs.  I wished I was headed there, up above a lot of haze.  Oh well.  I arrived well before sunset and dozed in the car.  There was still a wildflower superbloom in progress, with pretty sheets of yellow, purple, and pink flowers spread over the grassy hills.  Cattle grazing in the wide expanse, very bucolic.  Not to mention all the pollen in the air, but I had prepared with myself with eye and nose drops.  Not many cars passing by.  I ate and started to set-up, Akarsh arriving just after sunset with his 18-inch dob.  I used my 4- & 8-inch combo refractor and night vision.  While still during civil twilight I observed the Horsehead, showing off.  I continued my Sharpless project, missing a few items which had set by the time I got to them.  Observed a few other things.  I enjoyed observing with Akarsh, who is a serious and adventurous observer.

Highlights to start, then the rest of the items:

Fal 1: 06:58:50 -06:33:33: This is a recently discovered OIII cloud and is included on Arkash’s “Insanity” CalStar observing list. Apparently, the discoverer takes astrophotos of random parts of the sky, just to see what might be there. Using my 4-inch with PVS-14, I confirmed the star field with Akarsh’s laptop & planetarium software. I flipped through my filter wheel, and when I got to the Ha+OIII dual band filter, the nebula popped into view. It was pretty large, faint but obvious. There were two ragged sections of diffuse nebula, shaped like parenthesis, forming a large broken circle. The section to the west is considerably thicker and brighter, with mottling and streaking, while the eastern section is thinner, fainter, and more uniform. I didn't have the discovery image with me, and I did not notice the central round "ying-yang" nebula as anything separate from the main. Next time I'll take a more careful look. I don’t think it’s been determined what the cloud is, but my guess is an ancient and/or nearby planetary nebula, the clouds of which have started to break up against the interstellar medium.

Sh2-247: 06 08 30.2 +21 37 12, 9’: With 8-inch and Ha, it appeared very bright, fairly large, round, full of billows of cloud giving the impression of a spiral galaxy, bordered on one side by a nearly straight dark cut-off and with a central star. A smoke of nebulosity trailed off from one side toward Sh2-252. Vogel says: “Distance: 2000 pc, Size: 5.2 pc. The Sh2-247 molecular cloud is part of the Gem OB1 complex, contains 37 thousand solar masses at a distance of 2200 pc and appears to be physically connected through CO filaments with Sh2-252. The exciting star is LS V 21 27 (B0 III star).” Surprisingly, given how bright this appeared to me, Vogel reports “no certain observation” with his 22-inch.

Late at night, as the Milky Way rose, I scanned around with the PVS-14 mounted on a monopod, viewing 1x with an Ha filter. I enjoyed all the favorites: North America with the nebula connecting it to Cepheus on one side and Sadr on the other; the Veil Nebula; the very bright Lagoon, etc. I was able to observe two Sivan nebula which had set by the time I tried to observe them last summer:

Siv 10: 16 01 00.0 -20 19 00, 840'720’, 14° x 12°, 174 pc.
This nebula lies in between the Scorpion’s head and Sh2-27, the large bright cloud which many observers with night vision have noticed. It was faint, but obvious, large, round with an arc of brighter nebulosity along its NE rim. The center was mostly diffuse but had a slightly brighter and mottled “core,” and there was a bright puff to the south. Sivan says of it; “Almost circular emission region containing two concentrations, S1 and S7 surrounding the stars Pi Sco and Delta Sco respectively. Appears to be associated with an expanding shell of neutral hydrogen connected with the II Sco association (Sancisi 1973).” Color image from Finkbeiner's H-alpha full sky map.

Siv 8: 16 43 24.6 -41 23 45, 420'x420', 7° x 7°, 2000 pc. This is at the southern tip of the Scorpion’s tail, and appears as an obvious, if faint, wreath-shaped cloud, with IC 4628 the Prawn Nebula as a very bright bow on it’s NE rim. There was a large sheet of nebulosity flowing further south to the horizon, a bright knot of which is NGC 6188. I also examined this through both the 4-inch and 8-inch scope, seeing a lot more wisps and billows, and very excitingly the pillar of dark nebulosity along the northern rim, which looks like a much larger version of the Cone Nebula. Sivan says: “Wheel-shaped nebula, possibly connected to RCW 114 by faint, outlying filaments. Contains RCW 113 and IC 4628. Connected with the Sco OB1 association. The derived linear diameter is 244 pc.”

Sh 2-248 = IC 443: 06 16 38.4 +22 30 01, 50’. Known as the Jellyfish nebula, for its bright dome with fainter wisps floating down from it toward the bright star Propus. These filaments curve and flow laterally away toward the bottom (SW section of the nebula). Vogel reports the southwest filaments as being extremely faint with his 22-inch, but they were quite easy for me. Vogel: “Distance: 1500 pc, Size: 21.8 pc, “3000-year-old Gem A supernova remnant (SNR 189.1+03.0).”

Sh 2-249 06 20 58.1 +23 05 23, 80’. Sh2-249 was in the same field with Sh2-248 with the 4-inch, and appeared large, diffuse, and bifurcated by a tree-like dark nebula (like a larger, fainter version of the Flame Nebula), near the bright star Mu Gem. Vogel: "Distance: 1600 pc, Size: 37.2 pc. This HII region is excited by members of the Gem OB1 association."

Sh2-268: 06 10 14.6 +13 19 55, 60’: Incredibly faint, large ring, seen with 4-inch and Ha and only by moving the scope to notice it. Brightest section to the east mingled with a ragged stream of 5 stars. Distance: 1300 pc, Size: 22.7 pc.

Sh2-302: 07 31 41.0 -16 58 43. 21’: 8-inch Ha, an irregularly round glow, irregularly bright, with two bright stars at NE and SW sides, and sprinkled throughout with fainter stars. There is a distinctive dark lane splitting the eastern rim from the rest. Vogel: “Distance: 1800 pc, Size: 11.0 pc. Also called RCW 7, Sh 2-302 is part of molecular cloud A in front of supershell GS234-02.”

PuWe 1: Purgathofer-Weinberger 1 = PGN 158.9+17.8, 06:19:36 DEC +55:37:00. Tried for it at Akarsh’s suggestion. With 8-inch and Ha, it was an extremely vague, medium-sized (half a degree?) round glow with diffuse edges, noticed when moving the scope but can then hold it direct. Image from Andre van der Hoeven, who gives some additional information about the object: "The nebula has an estimated diameter of about 4 ly, and therefore is probably a very old remainder of a planetary nebula that has expanded that far that the remaining gases are only weakly energized by the central star."

Sh2-242: 05 51 50.7 +27 00 38, 7': Appears as a ragged, mottled fan with the 4-inch and Ha. With the 8-inch, it is much brighter, and the thicker sides pop out from the murkier middle. The long back edge of the fan is diffuse with faint trailings of nebulosity dragging behind it east.  Vogel: "Distance: 2100 pc, Size: 4.3 pc. This HII region is excited by a B0V star and appears to lie at a distance of 2700 parsecs."

Sh2-241: 06 04 06.7 +30 14 52, 10": With 4-inch and Ha, faint but quite apparent, larger than Sh2-242, looks like a comet emanating from a small bright cloudy come, with a blunt, fan shaped tail extending southwest, the sides of which are much brighter than the rest.  Vogel: Distance: 4700 pc, Size: 13.7 pc.  The exciting star for this nebula is the O9V star LS V +30 31. The nebula is a blister on the side of a molecular cloud at 5300 +/- 1100 parsecs. This field also contains the reflection nebula vdB 65 at 1100 parsecs, which is a completely unrelated object."

Sh2-244: M1 = NGC1952 = Crab Nebula, 05 34 30.4 +21 57 09, 5': Irregularly shaped oval, mottled interior, soft edges, viewed in both 4- and 8-inch, Ha+OIII dual band.  Distance: 1930 pc, Size: 2.8 pc.  This is the Crab nebula supernova remnant. 

Sh2-245: 04 02 32.8 +04 07 42, 720': 4-inch Ha, a very weak and long streak, seen when moving the scope only to notice the contrast change.  The streak has different thicknesses and is somewhat mottled.  This is just a small section of the Eridanus Loop, which is much better seen -- it's pretty bright, actually -- at 1x.  Too much magnification and a smaller image scale is not the right way to observe this object. 

Sh2-246: 05 02 08.9 +14 05 44, 65' 4-inch and Ha only, very extremely faint contrast change running N-S to the background sky, through a very pretty zig-zag pattern of stars which run NW-SE.  With attention I notice mottling or unevenness, and it's quite large.  Vogel: Distance: 3700 pc, Size: 70.0 pc.  Sh 2-246 is visible in the direction of Lynds dark cloud LDN 1562, which together with Lynds dark cloud LDN 1563 forms a local dust ridge located well below the galactic plane at a distance of 180 pc, and is part of the Taurus dust cloud complex within the Gould belt, our local stellar neighborhood. Avedisova concludes that Sh 2-246 and LDN 1562 are part of the same star formation region, SFR 186.96-16.58. If Sh 2-246 is actually embedded in this dust ridge, it must be much closer than the distance estimate given here.

Sh2-265: 05 18 36.3 +07 26 23, 70': 4-inch and Ha, Broad, diffuse, large, running mainly W-E, bifurcated with a brighter / thicker wing to the N, and fainter more uniform wisps to the south.  Vogel: Distance: 400 pc, Size: 8.1 pc.  This diffuse HII region is part of the B223 section in the southern part of the Lambda Orionis ring (most of which forms the huge Sh 2-264 HII region). However, Sh 2-265 is not ionised by Lambda Orionis itself. Instead it is probably ionised by stars in the Ori OB1b association.

Sh2-266: 06 18 48.9 +15 16 40, 1': 8-inch only, difficult, very small non-stellar glow around a star, identified only with comparing the star field to the POSS image, no detail seen.  Vogel: Distance: 6000 pc, Size: 1.7 pc.  This may be a ring nebula surrounding its central star, the Be class supergiant MWC 137."

Sh2-267: LBN 875 = PK 196-01.1 06 15 52.7 +14 16 06, 4', Distance: 4500 pc, Size: 5.2 pc

Sh2-269: 06 14 34.1 +13 49 18, 4', Distance: 3800 pc, Size: 3.9 pc.

Both are fairly difficult, seen as very small puffs with the 4-inch & Ha, brighter with the 8-inch, with -269 being more densely bright and -267 more diffuse.  The dark lane splitting -269 was well seen.

Sh2-270: 06 10 12.9 +12 48 55, 1': Small round non-stellar glow, 8-inch Ha only, identified by comparing the star field to the POSS image.  This really requires a larger aperture.  Distance: 6800 pc, Size: 2.0 pc.

Sh2-271: PK 197-02.1 06 14 54.3 +12 21 14, 2'

Sh2-272: 06 15 00.3 +12 20 14, 1'

-271 is larger but just a faint puff seen with the 8-inch only, -272 is much smaller and seen with averted vision and only after studying the POSS image for its location.  Vogel: Distance: 4800 pc.  Includes infrared cluster [BDS 2003] 82. There is confusion in the literature about whether this is an HII region or planetary nebula

Sh2-273: NGC2264 = Christmas Tree 06 40 48.3 +09 54 28, 250': Fox Fur, which I have seen many times, all details seen with 4-inch & Ha, including the Cone Nebula.  Vogel: "Distance: 800 pc, Size: 58.2 pc.  The Fox Fur nebula is associated with the star cluster NGC 2264, dominated by the O7Ve multiple star system S Monocerotis (usually abbreviated to S Mon). This region also includes the famous Cone nebula, visible at the bottom of the image. 

Sh2-274: Abell 21, 07 29 06.4 +13 15 43, 8': 8-inch and Ha+OIII dual band, a mottled and streaked crescent moon nebula, rather large, with an excessively faint curved band opposite (NW band) trying to close the circle.  Vogel: "The Medusa nebula, Abell 21, is a planetary nebula located at a distance of about 188 pc and is 8800 years old." 

Sh2-278: 05 19 48.2 -05 39 49, 50': A few degrees east of M42, but never noticed: Wedge shaped with the brighter tip pointed east, and fainter wings spreading out from it and fading very slowly and faintly into the background. 4-inch Ha.  Vogel: Distance: 500 pc, Size: 7.3 pc, this is the high latitude cloud MBM 110."

Sh2-280: 06 34 18.7 +02 32 23, 40': Large diffuse cloud orientated NE-SW, bifurcated to two bright wispy halves, with a diffuse fog curling from the SW end up to the north.  4-inch Ha.  Vogel: Distance: 1700 pc, Size: 19.8 pc, The exciting star for this HII region is HD 46573."

Sh2-282: 06 37 58.5 +01 30 51, 35': Large diffuse nebula running N-S, with some wispy streaks and puffs of nebulosity to the north, it looks like a footprint.  Worth another look with more aperture as I missed the cometary globules.  Vogel: "Distance: 1500 pc, Size: 15.3 pc.  The exciting star of this HII region, HD 47432 (the bright star in the upper part of the image), is located at a distance of 1250 pc and is probably a member of the Mon OB2 association (whose distance is usually given as 1550 pc). The HII region contains a system of eight cometary globules."

Sh2-284: 06 45 02.0 +00 13 51, 80': Extremely weak large round glow, with an inner ring of faint stars. 4-inch Ha. Vogel: Distance: 5200 pc, Size: 121.0 pc.  This large HII region is associated with the star cluster Dolidze 25 and is one of the few relatively unobscured major star formation regions in the outer galaxy."

Sh2-285: 06 55 12.2 -00 30 37, 1' Small non stellar glow with a very short comet-like tale to the south, 8-inch Ha only.  Vogel "Distance: 6900 pc, Size: 2.0 pc. Contains at least two B0 V stars and the infrared cluster [BDS2003] 85."

Sh2-286: 06 54 32.6 -04 30 32, 6': Very faint round glow, a little brighter in its eastern half and diffuse and with fading edges to the west, 8-inch Ha.  Distance: 6600 pc, Size: 11.5 pc.  Contains the infrared cluster [BDS2003] 88.

Sh2-287:  06 59 32.3 -04 48 14: 12' Patchy cloudiness following an arc of five moderately bright stars, 8-inch Ha.  Vogel: "Distance: 2100 pc, Size: 7.3 pc. Sh 2-287 appears to be associated with Maddalena's cloud (G216-2.5). It contains 4000-5000 solar masses of gas and dust and a bipolar nebula, NS 14."

Sh2-288: IC 466 07 08 33.0 -04 18 30, 1': Small, bright glow around a star, and a very faint and small diffuse cloud around that brightest concentration, 8-inch Ha.  Distance: 3000 pc, Size: 0.9 pc. This HII region, also called IC 466, is ionised by an O9V star."

Sh2-289: 06 45 56.3 -07 20 18, 11': Fairly large amorphous round glow, with a stronger concentration to the south, mingled with many stars.  8-inch Ha.  Distance: 10100 pc, Size: 32.3 pc

Sh2-290: Abell 31 08 54 10.5 +08 55 16, 17': Fairly difficult, 8-inch Ha+OIII, diffuse round cloud with brighter/sharper southern rim, mottled central region, and diffuse and broken northern rim, with a distinctive L-shaped asterism in the middle.  

Sh2-291: 06 55 24.6 -08 01 40, 8': Small, faint, oval puff, diffuse to the south.  8-inch Ha.  Distance: 8500 pc, Size: 19.8 pc

Sh2-294: 07 16 34.3 -09 26 38, 7': Small bright clotted concentration of nebula, with a fainter lobe to the north, and a very faint wisp of cloud to the north of it.  Vogel: "Distance: 4600 pc, Size: 9.4 pc.  This HII region contains the loose infrared star cluster [BDS2003] 95. Its odd shape looks like an upside down octopus - should it perhaps be called the Octopus nebula?"

Sh2-313: Abell 35 12 53 31.0 -22 51 35, 12': Extremely faint, rather large round diffuse glow but with two bright streaks running E-W through the southern half.  Tough.  8-inch Ha. This is the planetary nebula Abell 35. Like Sh 2-52 (Abell 65), it has a highly unusual binary central star. It probably 

lies at a distance of 160 pc."

9 april 2023

Seeing was forecast as being average to start the night and improving to "good" after 10pm.  I opened up the 20-inch and indeed found the seeing to be average starting from 9pm, so I masked down to 7-inches and whipped through a large number of targets in my Struve list, mainly in Gemini and Lynx.  Many pairs were very wide and I wonder why Struve bothered to measure them.  But, there were some very pleasing close pairs, too.  After 10pm I was getting perfect star images with the 7-inch, and there was a very close Struve pair for which I needed to go up to 20-inches, which gave me some hope the forecast was correct.  I finished the list in Lynx then switched over to the "movement" list for some challenges.  As it got later I could smell the moisture in the air (it is to be cloudy tonight and Wednesday), a sign transparency was failing.  I closed up at midnight.

STF1144 AB 178; 140x: Faint pair, wide, 2 Dm.  There is 35% parallax range overlap, 1,466 AU weighted separation, 2.1+1.2 Msol, so there is some possibility it is binary and an orbit should be tried.

07h 49m 00.84s +28° 34' 26.4" P.A. 358.00 sep 8.4 mag 7.94,10.33 Sp F0 dist. 184.16 pc (600.73 l.y.)

STF1147 AB: 178; 140x: Fine pair, light orange stars split even with low power, near equal magnitude.  There is 34% parallax range overlap, only 159 AU weighted separation, 0.9+9.9 Msol, so it might be binary and an orbit should be tried.

07h 50m 19.69s +24° 31' 55.8" P.A. 175.00 sep 2.2 mag 9.66,9.68 Sp G0

STF1156 AB: 178; 140x: Wide, 2 Dm.  There is -95% overlap of the parallax ranges, it is not binary.

07h 53m 47.73s +24° 43' 57.2" P.A. 194.00 sep 34.6 mag 9.50,11.46 Sp G5

STF1163 AB: 178; 140x: This is the same as STF1156.

STF1000 AB-C: 178; 140x: Wide, nearly 1 Dm. Did not try for A1061AB but should have.  -25% parallax range overlap, it is not binary.  No Gaia data for the Aitken secondary.

06h 59m 21.15s +25° 14' 00.2" P.A. 67.00 sep 22.1 mag 8.09,9.02 Sp F8V dist. 223.21 pc (728.11 l.y.)

STF1155 AB: 178; 140x: Very wide, 1 Dm, A is light yellow.  There is no Gaia parallax data for the secondary.  Did not try for COU1111 Aa-Ab, but should have! 10.0/10.0 0.4".  

07h 54m 28.38s +26° 10' 01.9" P.A. 343.00 sep 16.8 mag 8.67,10.40 Sp K2 dist. 694.44 pc (2265.26 l.y.)

STF1113 AB: 178; 140x: Superwide, 2 Dm.  -97% overlap of the parallax ranges, it is not binary.

07h 34m 59.32s +24° 15' 55.8" P.A. 180.00 sep 92.2 mag 7.85,11.10 Sp M0 dist. 952.38 pc (3106.66 l.y.)

STF1158 AB: 178; 140x: Wide faint pair, equal.  There is 16% overlap of the parallax ranges, 4,066 AU weighted separation, 2.6+2.0 Msol, so there is some possibility to be binary and an orbit should be tried.

07h 56m 31.40s +21° 52' 28.6" P.A. 334.00 sep 7.6 mag 9.30,9.30 Sp A5III

STF1081 AB: 178; Very pretty split with 140x eighteen but best seen with 280x, 1Dm, close, dull almost blue A and red B.  There is no overlap of the parallax ranges, -3%, which is a surprising result.  Only 328 AU weighted separation, 2.2+1.8 Msol, which are all good results, but it likely is not binary given the parallax.

07h 24m 08.94s +21° 27' 28.0" P.A. 234.00 sep 1.9 mag 7.68,8.52 Sp B9 dist. 210.97 pc (688.18 l.y.)

STF1140 AB: 178; 140x: Pretty light yellow stars, 2 Dm, well split.  There is 45% overlap of the parallax ranges, 1,160 AU weighted separation, 2.8+1.8, and the radial velocity delta 2.4 is just below the escape velocity 2.7.  It is likely binary and an orbit should be tried.

07h 48m 22.61s +18° 20' 12.4" P.A. 273.00 sep 6.4 mag 7.01,8.65 Sp K0III dist. 213.22 pc (695.52 l.y.)

STF1142 AB: 178; 140x: Random wide stars, more than a little delta.  There is no overlap of the parallax ranges, -98%, it is not binary.

07h 48m 22.92s +13° 25' 06.3" P.A. 211.00 sep 34.3 mag 8.37,10.91 Sp K0 dist. 230.95 pc (753.36 l.y.)

STF 946 AB: 178; 140x: Sharp white stars, 1 Dm, well split.  There is no parallax range overlap, -85%, it is not binary. 

06h 44m 51.62s +59° 26' 57.4" P.A. 129.00 sep 4.0 mag 7.30,9.11 Sp F5 dist. 101.11 pc (329.82 l.y.)

STF 923 AB: 178; 140x: White stars, 1 Dm, wide.  There is no overlap of the parallax ranges, -91%, it is not binary.

06h 38m 06.95s +59° 26' 57.9" P.A. 144.00 sep 33.0 mag 7.57,11.47 Sp G8III dist. 226.24 pc (737.99 l.y.)

STF 948 AB: 178; 200x: 12 Lyn.  Great pair, two near equal stars closely split, with a wider slightly less bright forming a triple.  Seen at 140x but best at 200x.  As a great surprise, there is no parallax range overlap, -3%, despite the 137 AU weighted separation and 2.4+2.1 Msol.  SOC gives it a grade 4 orbit, 733-year period.  I would say this one will likely turn out not to be binary.

06h 46m 14.15s +59° 26' 30.1" P.A. 64.60 sep 1.9 mag 5.44,6.00 Sp A3V dist. 65.83 pc (214.74 l.y.)

STF894 = S514 AB: 178; 140x: 5 Lyn.  Light yellow A and wide, very faint B.  AC is the 2 Dm pair about 3 times distant 130-degrees different.  There is no parallax overlap in any case, -70%, it is not binary.

06h 26m 48.88s +58° 25' 02.7" P.A. 140.00 sep 32.4 mag 5.38,11.90 Sp K4III dist. 191.94 pc (626.11 l.y.)

STF 936 AB: 178; 280x: Quite difficult, needed best seeing for the 2 Dm B to appear at A's first diffraction ring, and only when that ring subsides in brightness.  No Gaia parallax data for the secondary.

06h 39m 43.55s +58° 05' 42.1" P.A. 284.00 sep 1.1 mag 7.26,9.04 Sp G5 dist. 254.45 pc (830.02 l.y.)

STF1020 AB: 178; 140x: Wide, nearly 1 Dm.  There is no parallax range overlap, -62%, it is not binary.

07h 11m 56.72s +57° 30' 27.5" P.A. 285.00 sep 13.3 mag 8.76,10.44 Sp F5

STF 916 AB: 178; 140x:  Well separated pair, 1 Dm.  There is no overlap of the parallax ranges, -14%, it is not binary.

06h 34m 12.46s +56° 38' 46.1" P.A. 254.00 sep 9.4 mag 9.43,10.55 Sp A3

STF1002 AB-C, A1324 AB: 508; 560x: Exquisite.  The Struve is a wide equal magnitude pair, the primary of which is the Aitken, a close pair split with seeing, slightly unequal.  Nice! 

07h 04m 09.76s +56° 26' 24.9" P.A. 319.00 sep 30.2 mag 9.45,10.05 Sp G

STF1025 AB: 178; 140x: Wide near equal.  There is no parallax range overlap, -90%, it is not binary.

07h 12m 50.93s +55° 48' 12.2" P.A. 130.00 sep 27.0 mag 8.37,8.67 Sp K0 dist. 86.51 pc (282.2 l.y.)

STF 958 AB: 178; 140x: Well split, slightly unequal light yellow stars.  There is no parallax range overlap, -19%, so in spite of the close 196 AU weighted separation, 1.5+1.5 Msol, and that the radial velocity delta 0.1 is less than the escape velocity 5.2, it is not likely binary.

06h 48m 12.29s +55° 42' 15.1" P.A. 256.30 sep 4.5 mag 6.28,6.34 Sp dF5+dF6 dist. 44.27 pc (144.41 l.y.)

STF1062 AB: 178; 140x: White stars, slightly unequal, wide.  There is 13% overlap of the parallax ranges, 2,923 AU weighted separation, 3.6+2.8 Msol, so there is some chance it is binary and an orbit should be tried.

07h 22m 52.06s +55° 16' 53.3" P.A. 317.00 sep 13.8 mag 5.76,6.71 Sp B8V+B9V dist. 169.2 pc (551.93 l.y.)

STF 934 AB: 178; 140x: Faint close pair, near equal.  There is no overlap of the parallax ranges, -32%, it is not likely binary.

06h 39m 06.40s +55° 02' 30.2" P.A. 332.00 sep 4.1 mag 9.77,10.54 Sp A7

STF1009 AB: 178; 140x: Attractive, slightly unequal white stars, wide.  There is 27% parallax range overlap, only 429 AU weighted separation, 2.0+1.9 Msol, so there is some chance it is binary and an orbit should be tried.

07h 05m 39.83s +52° 45' 31.3" P.A. 148.00 sep 4.4 mag 6.87,7.01 Sp A3Vs dist. 99.7 pc (325.22 l.y.)

STF1050 AB: 178; 140x: Wide, white stars, slightly unequal.  There is 60% parallax range overlap, 4,324 AU weighted separation, 2.3+1.9 Msol, and the radial velocity delta 0.6 is less than the escape velocity 1.3.  It is very likely binary and an orbit should be tried.

07h 19m 51.29s +54° 55' 18.4" P.A. 21.00 sep 19.4 mag 8.08,8.80 Sp A0V dist. 140.85 pc (459.45 l.y.)

STF1001 AB: 178; 140x: Wide, slightly unequal.  There is 36% parallax range overlap, 2,174 AU weighted separation, 2.7+1.6 Msol, so it might be binary and an orbit should be tried.

07h 03m 05.51s +54° 10' 26.6" P.A. 66.00 sep 9.1 mag 7.82,9.40 Sp G0 dist. 148.59 pc (484.7 l.y.)

STF 960 AB: 170; 140x: Wide, white, nearly one delta magnitude.  There is 54% parallax range overlap, 2,904 AU weighted separation, 1.9+1.2 Msol, however the radial velocity delta 1.9 slightly exceeds the escape velocity 1.4, so it might not be binary but an orbit should be tried.

06h 49m 38.96s +53° 01' 52.9" P.A. 68.00 sep 21.8 mag 7.87,9.90 Sp F0 dist. 271 pc (884 l.y.)

STF 887 AB: 178; 140x: Faint stars, significant delta magnitude, B seen with averted vision at first then can hold direct.  There is no parallax range overlap, -97%, it is not binary.

06h 24m 19.47s +60° 07' 23.6" P.A. 210.00 sep 7.8 mag 11.05,12.90

STF1098 AB: 178; 140x: Wide, nearly one delta magnitude.  There is no overlap of the parallax ranges, -97%, it is not binary.

07h 34m 50.49s +59° 33' 19.5" P.A. 290.00 sep 27.2 mag 10.31,10.57 Sp K0

STF937 = STF923: as described above.

STF1033 AB: 178; 140x: Very fine white pair, 1 Dm, just split with 140x, pretty.  There is 33% overlap of the parallax ranges, only 280 AU weighted separation, 2.2+1.9.  It is possibly binary and an orbit should be tried. 

07h 14m 48.05s +52° 32' 44.1" P.A. 278.00 sep 1.5 mag 7.81,8.44 Sp F0 dist. 271 pc (884 l.y.)

STF 968 AB: 178; 140x: Wide, 1 Dm, with faint closer third star (BC) to the NE seen with averted vision.  A-C has no parallax range overlap, it is not binary.  AB has 50% parallax range overlap, 5,245 AU weighted separation, 2.3+1.8 Msol, and the radial velocity delta 0.8 is less than the escape velocity 1.2, so it is likely binary and an orbit should be tried.

06h 52m 52.01s +52° 40' 49.5" P.A. 289.00 sep 20.7 mag 8.28,9.19 Sp A3

STF1096 AB: 178; 140x: Wide, 1 Dm.  There is 4% parallax range overlap -- but with 6% error.  It is not likely binary.

07h 31m 54.77s +50° 09' 03.5" P.A. 327.00 sep 29.0 mag 8.00,10.62 Sp A0

STF1065 AB: 178; 140x: White stars, near equal, wide.  There is no parallax range overlap, it is not binary.

07h 22m 15.11s +50° 08' 55.7" P.A. 256.00 sep 15.1 mag 7.51,7.67 Sp A6II dist. 283.29 pc (924.09 l.y.)

STF1093 AB: 178; 280x: Slightly unequal, hairline split, really nice!  There is 28% parallax range overlap, 115 AU weighted separation, 1.5+1.4 Msol, so it is likely binary.  SOC has a grade 4 orbit 715-year period.

07h 30m 16.51s +49° 58' 42.0" P.A. 207.40 sep 0.9 mag 8.79,8.98 Sp F5 dist. 90.42 pc (294.95 l.y.)

STF1091 AB: 178; 140x: In the same FOV with STF1093. Wide, equal.  There is no parallax range overlap, -96%, it is not binary.

07h 29m 57.86s +49° 58' 08.8" P.A. 321.00 sep 30.0 mag 9.54,10.06 Sp G2V

STF1092 AB: 178; 200x: Very fine split at 140x, seen better with 200x, more than 1 Dm, nice close split.  There is -4% parallax range overlap, it is not likely binary.

07h 30m 22.47s +49° 14' 20.4" P.A. 71.00 sep 2.9 mag 8.56,10.45 Sp A2

STF1032 AB: 178; 200x: Close pair, >1 DM, white A and blue B.  Seen at 140x but better at 200x.  There is no parallax range overlap, -4%, it is not likely binary.

07h 13m 52.61s +48° 29' 55.8" P.A. 114.00 sep 2.7 mag 7.32,10.34 Sp A2V dist. 148.81 pc (485.42 l.y.)

STF1040 AB: 178; 140x: Well split, 1 Dm.  There is 7% parallax range overlap, 1,321 AU weighted separation, 1.7+1.2 Msol, and the radial velocity delta is less than the escape velocity 2.0.  It is likely binary and an orbit should be tried. 

07h 16m 20.14s +48° 12' 54.0" P.A. 261.00 sep 7.3 mag 8.79,10.34 Sp A3

STF1044 AB: 178; 140x: Wide, >1 Dm.  There is 69% overlap of the parallax ranges, 1,106 AU weighted separation, 0.9+0.9 Msol, it is likely binary and needs an orbit.

07h 17m 08.96s +47° 39' 18.1" P.A. 169.00 sep 13.1 mag 10.08,10.60 Sp K0

STF1161 AB: 178; 140; 1 Dm white stars, nicely split.  There is 70% overlap of the parallax ranges, only 419 AU weighted separation, 1.8+1.3 Msol, it is likely binary and needs an orbit.

07h 59m 40.77s +46° 37' 12.2" P.A. 198.00 sep 2.9 mag 8.21,9.82 Sp G0 dist. 110.13 pc (359.24 l.y.)

STF1071 AB: 178; 140x: Wide faint pair.  There is no overlap of the parallax ranges, -93%, it is not binary.

07h 23m 02.50s +44° 59' 43.3" P.A. 31.00 sep 20.6 mag 9.12,10.70 Sp G0 dist. 102.77 pc (335.24 l.y.)

STF1145 AB: 178; 280x: ! Extremely fine, split with 280x and seeing, 2 Dm.  Surprisingly there is no overlap of the parallax ranges, -54%, it is not binary.

07h 51m 19.02s +38° 49' 17.3" P.A. 42.00 sep 1.3 mag 8.73,10.39 Sp A3 dist. 311.53 pc (1016.21 l.y.)

STF1118 AC: 178; 140x:  the struve is the nice wide one delta  did not see the close hu pair 

STF1139 AB: 178; 140x: Wide faint pair.  There is no overlap of the parallax ranges, -96%, it is not binary

07h 49m 11.68s +37° 06' 21.1" P.A. 35.00 sep 17.3 mag 10.37,11.04 Sp F8

STF1117 AB: 178; 140x: 1 Dm, wide.  There is no overlap of the parallax ranges, -61%, it is not binary.

07h 36m 43.19s +35° 23' 30.0" P.A. 228.00 sep 11.6 mag 9.10,10.59 Sp F0

STF1356 AB: 178; 140x: 1 Dm, hairline split to the ESE. easy with seven eighteen, one delta and hairline split with PA to the ESE.  SOC grade 2 orbit 117.9-year period, it will hang in the SE apastron through the late 2040s, so the change will be subtle.  Better viewed from 2050 to 2070 when it tightens considerably.  No Gaia data for the secondary.

09h 28m 27.41s +09° 03' 24.4" P.A. 115.60 sep 0.9 mag 5.69,7.28 Sp F9IV dist. 33.17 pc (108.2 l.y.)

STF1344 AB: 178; 140x: Slightly unequal well separated pair.  There is no overlap of the parallax ranges, -47%, it is not binary.

09h 23m 28.35s +39° 08' 05.1" P.A. 102.00 sep 3.8 mag 9.03,9.50 Sp F2 dist. 136.99 pc (446.86 l.y.)

STF1374 AB: 178; 140x: Closely separated, 2 Dm, light orange pair.  SOC grade 4 orbit 1815-years.  But, there is no overlap of the parallax ranges, -77%, it is not binary.

09h 41m 21.88s +38° 57' 01.9" P.A. 312.30 sep 2.8 mag 7.28,8.65 Sp G3IV dist. 51.28 pc (167.28 l.y.)

STF1375 AB: 178; 140x: 1 Dm, white, wide.  There is no overlap of the parallax ranges, -69%, it is not binary.

09h 41m 52.96s +34° 34' 29.3" P.A. 306.00 sep 7.2 mag 8.50,10.25 Sp A2 dist. 219.78 pc (716.92 l.y.)

STF1382 AB: 178; 140x: 1 Dm wide.  There is no overlap, -97% of the parallax ranges, it is not binary.

09h 49m 02.87s +34° 05' 07.9" P.A. 94.00 sep 33.5 mag 7.22,10.67 Sp A7V dist. 88.03 pc (287.15 l.y.)

KUI 48 AB: 508; 1000x: Difficult, very mildly elongated, difficult to tell PA but seems along an E-W line.  SOC grade 2 orbit 17.835-years.  No Gaia parallax data for either star.  It will close through 2026 then widen to SE apastron by 2033.

10h 08m 15.94s +31° 36' 15.4" P.A. 181.80 sep 0.1 mag 6.90,7.20 Sp F4V dist. 61.24 pc (199.76 l.y.)

STF1728 AB: 598; 850x: Diadem.  At all powers 850x and above, I see a notched elongation on a NE to SW line.  The notch grows stronger with each magnification increase, and the stars appearing more as orbs.  SOC grade 1 orbit 25.85-year period, edge-on orbit, it is currently closing and will be wide enough to detect again in 2028.  No Gaia parallax data for either star.

13h 09m 59.28s +17° 31' 46.0" P.A. 192.20 sep 0.4 mag 4.85,5.53 Sp F5V+F6V dist. 17.83 pc (58.16 l.y.)

COU 596 AB: 508; 1000x: At all powers higher 1000x, it is very weakly misshapen from round, and I cannot tell any position angle.  No Gaia data for the secondary.  SOC grade 3 orbit, 38.13-year period.  it is rapidly closing and will be just splittable in the early 2040s at SW apastron.

12h 40m 55.44s +27° 08' 20.9" P.A. 194.40 sep 0.1 mag 8.50,8.70 Sp F5V dist. 151.06 pc (492.76 l.y.)

8 april 2023

We seem to have come through the rainy season at last.  It was clear last night with some haze, 3/5 transparency, but good seeing.  Better than good, actually.  I used the 20-inch and was able to chase after some close pairs.  The power on the Servocat kept cutting out, which was frustrating.  It is likely due to it sitting for so long and the metal contacts getting corroded.  

During the long interval between observing I have been going through the 6th Orbital Catalog is more detail.  Previously I had assembled my observing list only from checking a minimum separation value, 0.2".  But doing so will leave off pairs which are at an undetectably close periastron which, over the years, may separate enough to be seen.  I sorted the Catalog by period and, with orbital grade of 3 or better, looked up the orbit on Stelle Doppie for anything with a less than 200-years period.  I wanted to sort out pairs which would not make any significant movement in the next 20 years, and keep anything which might be resolvable at some point with a 20-inch scope.  I ended up with more than 500 pairs, 445 of which are visible from my latitude.  I've loaded this list on SkyTools and will use it nearly every time I observe with the 20-inch as seeing allows.  Many of the pairs deserve annual observations give the pace of their movement.  Besides, I need to track stars at periastron to have a more complete record of their movement.  And, it is not often that seeing will permit viewing of such pairs.

Which brings me to my dilemma.  Good seeing is rare for my observing site.  There are many pairs on the list where apastron is <0.25".  How am I to resolve those?  Unless I can observe with aperture from a mountaintop site with good seeing -- to get above the Bay Area haze.  Such a place is Fremont Peak, but it would mean I need to transport my 20-inch.  Or, I need to have another scope.  The 30-inch at the Peak would be preferable, but I have been so frustrated each time I used it -- difficult to move and point, poor eyepiece placement, crummy focusers, inability to view to the north.  I wish it was not the case, since it drives me to make an expensive choice.  I happen to have two 20-inch mirrors (I haven't sold Swayze yet) -- though at 2" Pyrex it is not the best choice for cooldown, the 1" Zambuto quartz beats it by a mile.  I'm thinking as I type this I could always just move the Zambuto between two different telescope structures, one for home and one for travel...an interesting idea.  It all has me shopping for different solutions.  I have some time to think about it since the road to Fremont Peak was washed out in the storms and it's not clear when it can reopen.

In any case, it was really nice to be back out observing.  Seeing is good again today so some solar observing will be coming up later this morning.

FIN 325 AB: 508; 400x: Using 400x and higher magnifications, the pair appears consistently as a rod with PA just east of north.  There is a nearby field star to mark the place.  Some atmospheric dispersion at highest powers but not influencing the observation.  SOC grade 2 orbit 31.43-years, it is NE now and will be closing to the E through the rest of the 2020s, widening through the 2030s to the S, apastron 2042.

07h 52m 47.87s -05° 25' 41.5" P.A. 356.60 sep 0.1 mag 7.32,6.19 Sp F5IV dist. 39.71 pc (129.53 l.y.)

STF1196 AB: 508; 280x: Zeta Cnc. Lovely near equal pair, light yellow-white color, with a third of similar color and magnitude off to the side.  SOC grade 1 orbit, 59.42-years, it's at N apastron now and will close slightly a quarter turn W by 2040. 

08h 12m 12.79s +17° 38' 51.2" P.A. 0.90 sep 1.1 mag 5.30,6.25 Sp F8V dist. 25.08 pc (81.81 l.y.)

A 2554 AB: 508; 850x: It seemed obviously enlongated WSW with a weaker end to the W.  No notching.  SOC grade 3 orbit, it is at W apastron now, will widen S by 2029 and SE periastron 2040. 

08h 53m 51.95s +01° 49' 28.0" P.A. 316.80 sep 0.1 mag 7.44,9.64 Sp F0 dist. 67.61 pc (220.54 l.y.)

AC 5 AB: 508; 560x: Just enough magnification to split the pair.  There is a significant magnitude difference, PA northward, with a field star to mark the position.  SOC grade 2 orbit, 77.82-years.  It is closing from NNE to apastron in the early 2030s, splitable again in the late 2040s to the SE.

09h 52m 30.47s -08° 06' 17.7" P.A. 34.30 sep 0.5 mag 5.43,6.41 Sp A1V dist. 85.11 pc (277.63 l.y.)

 

STF1523 AB: 508; 140x: Alula australis.  Quite easy, PA to SE and 1 Dm.  SOC grade 1 orbit, it is at SE now and will slowly widen to the E into the early 2040s.  

11h 18m 10.90s +31° 31' 45.0" P.A. 148.80 sep 2.2 mag 4.33,4.80 Sp F9V+G9V dist. 10.42 pc (33.99 l.y.)

HU 1134 AB: 508; 1000x: Viewed at all high powers, it is obviously not round but I could not pin down the PA exactly, it seemed on a NW to SE line but very tough.  SOC grade 3 orbit 81.47-year period, it is edge on and will be at periastron in 2028 before diving to apastron and be essentially undetectable for the rest of its orbit. 

11h 32m 12.54s +36° 14' 50.4" P.A. 300.00 sep 0.2 mag 7.24,7.85 Sp G8III dist. 177.3 pc (578.35 l.y.)

KUI  44 AB: 508; 1000x: 20 Leo.  Using all all high powers, seen as an elongation with a weak end consistently to SW.  SOC grade 3 orbit 113.1-year period, it will widen in the same direction to apastron in 2050.

09h 49m 50.12s +21° 10' 46.0" P.A. 225.50 sep 0.2 mag 6.62,7.31 Sp A7IVn dist. 191.57 pc (624.9 l.y.)

KUI  48 AB: 508; 1000x: At all high powers, appears as a very subtle egg shape, PA seems NW.  SOC grade 2 orbit 17.83-year period.  It will hang NW the next couple of years until reappearing SE 2031 apastron.

10h 08m 15.94s +31° 36' 15.4" P.A. 181.80 sep 0.1 mag 6.90,7.20 Sp F4V dist. 61.24 pc (199.76 l.y.)

KUI  37 AB: 254; 280x: 10 UMa. Using a 10-inch mask to deaden the primary's diffraction, B seen as a difficult point at the first diffraction ring PA NW.  Difficult needed to try all my tricks.  SOC grade 1 orbit, 21.8-year period, it is NNE PA now and will slightly widen to the N in late 2024, before tightening W and S during the 2030s--given the magnitude difference it will be difficult to see.

09h 00m 38.42s +41° 46' 57.6" P.A. 53.30 sep 0.6 mag 4.18,6.48 Sp F3V+K0V dist. 16.07 pc (52.42 l.y.)