12 Lyn and Porrima
Posted 27 April 2013 - 07:39 AM
Clear, Good Seeing [Actually great for NJ]
All observations made with home made 4” f/28 Schiefspiegler
12 LYN, STF 948
Sirius Plössl 40mm, 73x, Sirius Plössl 17mm, 172xSirius Plössl 10mm, 292x
Very nice. Three stars in FOV, but tight pair was not split at 40mm. AB pair was split at 292x, Major was gray-green, minor was more yellow. Very cool object. Seeing super for NJ. Returned to this object with Imaging Source webcam however could not split the AB pair, Only more obvious AC was split with the webcam.
Sirius Plössl 40mm, 73x, Sirius Plössl 17mm, 172x, Sirius Plössl 10mm, 292x
Major and minor seem similar in magnitude. They were split at 17mm, 172x. Split was definite at 10mm, 292x. Both major and minor similar color, somewhat yellow.
Posted 27 April 2013 - 08:21 AM
Posted 28 April 2013 - 02:45 PM
Thank you for pointing to this beautiful triple star.
All three stars very well seen in my 125mm F/7 Dobsonian at 236x/7.5mm Celestron ''orange'' Plossl+2x Japanese Barlow.
I guesstimated PA=330 degree for the C faint star,A and B looked close to the East-West direction, the main star being at West.The separation seem to me to be the same like that of Porrima.No other color detected except a very light yellow hue in the main star.
I had a bit of a hard time to locate this star through sucker holes.I wouldn't make it without my cheapo Sakura 9x60 mm binocular.
Great,great view,thanks again....and I want more!
Posted 28 April 2013 - 07:53 PM
Back then I noted the colours - including a slight greenish tone in the yellow of the primary star, and the 7th magnitude companion (at 8.5") a dull yellow with a touch of brown. Colours as always are somewhat subjective, especially with the subtle tones of many star colours.
I was interested that both reports, with 4-inch and 5-inch scopes, record the use of fairly high power to split the primary star into its near-equal components. This pair is listed at 1.8" separation, so I was surprised that it took over 200x to split it. Or was this the "best view" magnification? With the C8 I saw the close pair nicely split at 135x.
When you're looking at 12 Lyn, it's worth noticing in the same field just west the little pair STF 946, mags 7.3 and 9.1 at 4.0". Shouldn't be hard in a 4-inch. The C8 showed it just separated at 80x, and nicely split at 135x, still with 12 Lyn in the field (28' wide).
If you want to see another triple in Lynx, one I came across (back in my SoCal observing) was STF 1001 (RA 07h 03.1m, Dec +54 10). A-BC is an easy 8.7" pair of stars of mags 7.8 and 8.7; the BC is a close pair, individual magnitudes 9.3 and 9.4 (combined, 8.7) which are 1.6" apart in PA 355 - so it's near-enough a north-south pair.
I looked at STF 1001 the same night as 12 Lyn, and the C8 showed the BC pair of STF 1001 as a close just separated pair at 135x, though it was better at 200x. Because BC here is a lot dimmer than AB in 12 Lyn it will likely need more aperture.
Posted 30 April 2013 - 02:23 AM
Thank you for suggesting Struve 1001. Beautiful triple. It was going behind the trees to the Northwest of my garden by the time it was dark enough here (52N) to see the fainter components but lovely system!
Posted 30 April 2013 - 07:23 PM
It's only now occurred to me to see if Sissy Haas had listed this one in her book - yes she has, but only as an easy double - no mention of the double companion! A bit surprising, given that her description is from a 125mm refractor. However the magnification quoted is only 50x, and that won't show the companion as a double.
Curiously, TW Webb (way back!) does mention the companion as double and Haas's book makes quite a few references to Webb. So I guess this one slipped through the net. Easy to happen. The bonus might be for observers who look at STF 1001 with more magnification and "discover" the companion to be double.
Posted 02 May 2013 - 03:11 PM
My first observation of 12 Lyn it happened at 236x because that is my best magnification on the 125mm Dobsonian.
If I'm not able to split a double star at that magnification, not hope of succes with other eyepieces/magnifications.
I made more observations of 12 Lyn since and I was able to split it at 135x/Solid Simetric 12,8mm+2X Barlow.
Posted 16 May 2013 - 03:37 PM
This is a former ''Optus'' Newtonian.The optics are the original,I just optimized the OTA.
Other double-multiple stars split last night:
- with the 3 inch Newtonian : Epsilon 1-2 in Lyra,Porrima and Alula Australis in UMa,using a 7.5mm Celestron ''orange'' Plossl for 93x.
-in my 60x828mm refractor instead I saw Polaris B at magnifications ranging from 35x/ 24mm Galilean ocular -hardly visible- to 110x/Celestron 7.5mm Plossl-clearly visible.