Well, it has been quite a run of clear nights here on the Oregon coast - somewhere around 2 weeks in all. This unusual mid-winter clearing has been enjoyable with me logging 10 nights of observing. But it came to an end night before last. That night was mostly dedicated to a list of doubles in Auriga, but also ended with a wonderful Mars observation. Here's my report on all that.
2025-Jan-29
Ocean Observatory, Coos Bay, Oregon
Good transparency at first ending about an hour later with thickening clouds
No moon, cool, dry
Fairly good seeing improving as transparency got worse, at the end of the session when observing Mars through thick clouds seeing was excellent
AT115EDT triplet refractor
Theta Aurigae
Double star, 37 Aurigae, STT 545, WDS 05597+3713 – 2.6/7.2/11.1/10.1 magnitudes at 4.2/55/138 arc-seconds, at 52X with this exit pupil I have enough astigmatism in my eye to hide the A-B pairing, @ 105X both C- and D-components are seen well separated, A-B is still not apparent, @ 131X the C-component is in close just outside the glare of the yellowish primary, averted vision helps with that one, D is seen way out there, @ 261X A-B is split, but the triplet objective still needs more time to adjust to conditions, the diffraction rings are all on one side, but just outside the second diffraction ring there that little secondary is seen – a little spark, the primary image is a little unsymmetrical as far as diffraction rings, the Airy disc itself is nice & round, it’s a little reddish on the side away from the rings and secondary disc, as I continue observing the diffraction rings are beginning to be visible all around, A & B are nicely separated with some dark sky & diffraction rings between ‘em, not bad for the large Δ-V of 4.6 magnitudes, at this higher power with darkened sky I can just hold the faint C-component with direct vision, there are few notable field stars, this is a really nice quadruple, a lot of contrast in brightness and separations, well worth observing
Σ 0845
Double star, 41 Aurigae, STF 845 – 6.2/6.9 magnitudes at 7.5 arc-seconds, at 73X subject identified by the pattern of field stars in the FOV, @ 131X a nice nearly equal pair, there are three 7th magnitude stars in an arc off to one side, to me the companion looks a bit orange, @ 261X the primary is white while the secondary is a little bit yellow, some diffraction rings visible around primary and sometimes around secondary, back at 131X this is the best magnification to give some context around this well separated pair, a couple little headlights with one a bit brighter, well worth observing
Σ 0644
Double star, STF 644, WDS 05103+3718 – 6.8/7.0/10.5 magnitudes at 1.6/72 arc-seconds, at 73X it took quite some time to identify the subject in the FOV, @ 131X this is resolved, a nice tight pair, the C-component is also seen out a ways, both A & B look a bit orange which belies its 0.35 color index, the triplet has acclimated and stars are focusing down real tight, seeing must be good, @ 261X that little puppy is nicely separated with C well out there in a dark sky, the Δ-V of A & B looks to be greater than the listed 0.2 magnitude, they are noticeably different in brightness, but the primary is now assessed as being yellow-orange with secondary being blue, this is a really nice triple star with good seeing supporting splitting the close pairing, being near the zenith helps as well
Σ 0666
Double star, STF 666, ADS 3853, WDS 05172+3320 – 7.8/7.9 magnitudes at 3.0 arc-seconds, immediately recognized at medium power 131X, two little headlights, dim with some dark sky between ‘em, on the edge of the FOV is the bright orange star 16 Aurigae (STT 103)
OΣ 0103
Double star, 16 Aurigae, STT 103 – 4.8/10.6 magnitudes @ 4.1 arc-seconds, C.I. = 1.27, at 261X in same FOV as double star STF 666, this one has a huge 4.8 magnitude Δ-V, at this high power I’m seeing the diffraction rings morphing around, once in a while I see a little dot out there among them, but it could be just part of a ring, so I’m calling this one not resolved, a large aperture might do better in showing that faint companion, in the 261X FOV is another double star – ADS 3879
ADS 3879
Double star, ES 59, WDS 05187+3331 – 8.5/9.6 magnitudes @ 13.9 arc-seconds, at 131X in same FOV as double star STT 103, lower power is adequate for this wide pair, good brightness contrast, great separation, there are virtually no field stars save some faint ones, primary is yellow-white, this is an interesting duo
Σ 0718
Double star, STF 718, WDS 05323+4924 – 7.5/7.5/11.2 magnitudes @ 7.7/117 arc-seconds, C.I. = 0.49, at 261X in same FOV as STT 103 (16 Aurigae), this is a little set of headlights along with the distant C-component which can be held with direct vision, really good separation, there’s a slight difference in color A & B, but this is uncertain for such dim components
When I completed my list of doubles (along with others seen in the FOV, I decide to take a quick Look at Mars. Here's what I saw.
A few days past Mars' closest approach to Earth, 13.8 arc-seconds, at 261X the North Polar Cap is seen along with some albedo markings – Syrtis Major is apparent, @ 403X Mare Tyrrhena next to Syrtis is seen, perhaps the best view of Mars since 2003 using a 10-inch reflector, seeing is very good, at the same time clouds are covering the sky with Mars shining through, this is the highlight of the evening
So this evening was a wonderful way to end my January, 2025 string of clear nights. I have been using SkySafari's Observing-Planner utility to pare down the list of doubles in a particular constellation to those appropriate for my little refractor.
The more usual PNW winter rainstorms have returned, But I hope you-all have enjoyed my observations.
Best Regards,
Russ
Edited by Rustler46, 31 January 2025 - 10:11 PM.
