Monday, November 18, 2019

short period doubles

I started a new project I hope I will follow through the rest of my life.  I ran a search on SkyTools for binary pair with orbital periods of less than 60 years and separation of greater than 0.2" in northern constellations.  The result was around 150 pairs within grasp of my 20" scope.  Because the period is so short, I should be able to notice positional change within the next 10-20 years -- assuming I make careful sketches of the star fields and keep the records accessible.  One hazard is that some might be too close now, and may take several years before I can resolve.  Nevertheless, noticing change in the sky really excites me, and having just observed the Mercury transit has me thinking of both time and change.  I was able to record one such pair, A 2329, during last night's session.

Seeing was forecasted to be better than I had, 5-6/10 -- though observing over my rooftop was noticeably worse.  Transparency was middling to poor, with typical marine haze in the air, and some dewing.  My pointing accuracy over longer slews is rather poor -- I plan to do the super calibration later this winter once I have trimmed down some bushes and trees so I have the maximum view.  I remade my 8" mask and it worked well.  I observed from 9-11pm, when I needed to get to bed since it was a work night -- the laptop battery died at this point anyway.

STF 36: 20" 333x. =51 Psc. Bright white A and 3 detla mag B, wide. [This was on the short period list but I did not see this one. The short period pair is MCA 1 Aa,Ab, magnitudes 5.84 / 7.99. It was 0.3" at discovery in 1977, so it might've been a feasible pair in large aperture. But currently it is 0.12". The pairs I noticed are the more pedestrian Struves. This one will become splittable in a few years]
00h 32m 23.75s +06° 57' 19.6" P.A. 84 sep 27 mag 5.68,9.52 Sp B9.5V dist. 80.97 pc (264.12 l.y.)

STF 2947
AB: 8" 333x: Near equal and well split bright white stars.
22h 49m 00.68s +68° 34' 12.2" P.A. 56 sep 4.7 mag 6.91,7.02 Sp F4V dist. 63.69 pc (207.76 l.y.)

STF 2948: 8" 333x: Easy pair, white and slightly blue, 2 delta mag, ~2.5"
22h 49m 36.21s +66° 33' 13.8" P.A. 3 sep 2.6 mag 7.26,8.60 Sp B6Vn dist. 261.78 pc (853.93 l.y.)

STF 2950 AB: 8" 333x: Nice pair indeed. Bright yellow-white A and 2 delta mag B, clean split, ~2". May be third fainter much wider split (AC, 39.2" 11.05)
22h 51m 22.51s +61° 41' 47.9" P.A. 272.3 sep 1.13 mag 6.03,7.08 Sp G8III-IV dist. 72.73 pc (237.25 l.y.)

STF 2961 AB: 8" 333x: KZ Cep. Precisely equal pair, seems more than 2". Very nice.
22h 56m 30.92s +62° 52' 06.9" P.A. 349 sep 1.9 mag 8.48,8.61 Sp B0V

MLR 266 AB: 20" 333x: Tried with 8" at first but the faint B star apparent only at full aperture. A star turned a bright yellow-orange and the B star was an obvious steady bright star ~3". At 8" A's color is duller and I can only suspect the B star only after having first seen it at 20". There are other pairs in the system but at 15th mag are out of grasp of a red-zone back yard.
22h 56m 47.19s +62° 43' 37.6" P.A. 355 sep 2.9 mag 7.77,11.35 Sp O7n dist. 436.68 pc (1424.45 l.y.)

A 634 AB: 20" 333x: B star very faint even at full aperture, but can see it well with seeing, ~2". A is blue-white and much brighter with full aperture.
22h 56m 52.31s +59° 41' 27.4" P.A. 300 sep 2.1 mag 8.47,12.00 Sp A0

HJ 1838 AB: 8" 333x: Nice pair, more near equal, about a half delta mag, ~1.5" very nice
22h 58m 28.30s +67° 05' 16.9" P.A. 255 sep 1.5 mag 9.11,9.39 Sp G0 dist. 122.4 pc (399.27 l.y.)

KR 62 AB: 8" 333x: V711 Cep. Neat pair, wide, half delta mag, in the upper right corner of a Corvus asterism, [Eclipsing binary of Algol type, though I can't tell if the eclipsing star is the B star? Only one pair in WDS.  Further:, says . "Since it is unlikely that independent intrinsic variations of the optical companion could match the eclipsing binary in such a selective way, real intrinsic light changes for the eclipsing binary system are highly probable. Observations did not allow to determine which of the visual components of GSC 4282 394 is the Algol-type variable, and it was not possible to deduce it from the Tycho observations either, which do not show the detected variability but a high scatter and spurious oscillations" -- so the AB pair is not eclipsing, but either component may be variable?]
23h 05m 15.30s +63° 23' 42.3" P.A. 325 sep 5.5 mag 9.55,9.87

HJ 1860 AB; 8" 333x: White with wide blue pair, about 1 delta mag
23h 13m 32.24s +62° 39' 43.8" P.A. 335 sep 7.4 mag 9.11,10.60 Sp F0

MLR 71
BC: 8" 333x: Very faint pair, need averted vision to see B star, well split.
23h 12m 42.99s +63° 16' 35.9" P.A. 220 sep 2.9 mag 9.71,10.00 Sp G5

J 859
AB 20" 333x: Elongated smudge at 8", need full 20" to cleanly see as nice sharp points, well separated ~2", equal magnitude
23h 12m 13.63s +62° 17' 53.6" P.A. 155 sep 1.9 mag 11.04,11.65

ES 149 AB: 8" 333x: Nice equal pair, well separated ~6"
23h 39m 56.79s +64° 18' 48.8" P.A. 122 sep 5.6 mag 8.95,9.47 Sp F8

AG 290 AB 8" 333x: Widely separated half delta mag pair
23h 11m 02.35s +65° 54' 39.5" P.A. 265 sep 14.7 mag 9.25,10.01 Sp F0

HU 993: 20" 333x: B star only resolves with full aperture to a sharp point, very clear, well separated ~2", 2 delta mag.
23h 01m 42.54s +67° 47' 43.0" P.A. 215 sep 2.1 mag 8.85,10.29 Sp F8 dist. 124.69 pc (406.74 l.y.)

A 789: 20" 333x: Tried at 8" but it was a smear, needed 20" to resolve into very clean yellowish stars, about a half delta mag, ~2"
23h 24m 21.55s +69° 17' 11.1" P.A. 85 sep 2.2 mag 9.10,9.48 Sp A2

STF 91
AB: 8" 333x: Well separated 1.5 delta mag, white stars
01h 07m 10.99s -01° 43' 55.6" P.A. 315 sep 4.3 mag 7.43,8.56 Sp F9V dist. 48.71 pc (158.89 l.y.)

HJ 633 AB: 8" 333x: 1 delta mag wide
01h 09m 10.45s -02° 53' 08.5" P.A. 143 sep 9.5 mag 9.64,10.59 Sp F8 dist. 92.68 pc (302.32 l.y.)

A 2329 AB: 20" 1067x: Split at 533x but used barlow to confirm the PA accurately since this is a short period pair. Nicely split orange stars, half delta mag. Seeing it now at nearly the furthest extent of its orbit, it will become more difficult with time.  The pair is a "mere" 55.91 lightyears away.
02h 27m 45.86s +04° 25' 55.9" P.A. 102.4 sep 0.53 mag 9.45,9.63 Sp K5 dist. 17.14 pc (55.91 l.y.)
grafico orbita

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