Theta Aurigae Headache!

[Sunshine]

Last summer it was Theta Her which cause me many nights left cross eyed trying to split this difficult double till one night of great seeing I finally split them. Tonight it was back to the drawing board with Theta Aurigae which is TOUGH!!, I followed this star for what must have been 35 degrees with no luck. Using my 3.5mm XW at 230X rendered a nice pinpoint Theta Aur A, "B" caused me a headache, what i did notice was a dancing bulge ( I'll use positions on a clock) between 2 and 5 O'clock position where at times for a split second (pardon the pun) I was able to see a gap. Maybe on a better night I'll be able to see B as a pinpoint? what should my expectations be assuming seeing is good using a 4" refractor?, this one is a doozy but, I sure love a tough double. While researching this double I ran into stories others splitting it at powers of 130-175 which I guess would depend on seeing and, aperture used, I'll be darned if I came close with those powers. Either way I'm in it for the long haul now, the second appendage to the main star was spinning and morphing rapidly which indicates seeing needs to be a lot better.

Edited March 9, 2021 by Sunshine

[Nik271]

Theta Aurigae is a bit of a tough one, certainly possible in a 4 inch scope but you need very stable seeing. The first time I tried I  couldn't split it in a 7 inch Mak when the seeing is bad. It took me three attempts. These days its almost overhead in early evening which also helps. The separation between the A and B is fairly large about 4'' but the difficulty is that B at mag 7.2  is much much fainter than the primary ( mag 2.6) so it tends to get lost in the light of the primary.

Good luck with this one - it is a nice challenge and very satisfying to manage it!

[Pixies]

Last friday night I managed to split it quite easily - around x170 magnification. It was a night of very good seeing.

Was an 8" dob, though.

It was a tiny but bright pin-prick of light on the edge of the glow around the primary star - but very distinct, impossible to miss. I did a sketch, but it doesn't convey it's diminutive size.