Caw, Caw, Caw..ling Triple Star Fans

The relatively good weather this Spring has provided several observing opportunities, and I have finally got around to writing a report. On Sunday night, I roosted in Corvus, the Crow, for a couple of hours. The seeing was only moderate, and some of the targets were quite low, but I managed to pass two personal milestones, 1,500 observations logged, on 1,250 objects. Although Corvus is small, it does include some nice double stars, a lovely triple, and the remarkable "Stargate" double triple. Brief details are listed below. Thanks for reading, Mike.

Dbl: HJ4481 AB, RA 11:57:18, Dec -22:32:17, Mag1 8.3, Mag2 9, Sep 4". 2015-04-26, C11, 21mm Hyperion, 133x, Rating 3. Similar yellow stars, nicely split at 133x.

Triple: STF1604 AB, RA 12:09:29, Dec -11:51:25, Mag1 6.9, Mag2 10, Sep 9". AC, Mag1 6.9, Mag2 8.1, Sep 10.3". 2015-04-26, C11, 21mm Hyperion, 133x, Rating 4. Very pretty triple. The bright, sun-yellow primary is accompanied by two much fainter yellowish companions, the three forming a tiny triangle that is almost equilateral. It is resolved at 50x, but better (tonight) at 133x. Companion B at 9.3" is physical, C at 10.7" is optical.

Dbl: S634 AB, RA 12:11:23, Dec -16:47:27, Mag1 7.2, Mag2 8.8, Sep 4.7". 2015-04-26, C11, 21mm Hyperion, 133x, Rating 3. Unequal pair of rich golden stars, nicely separated at 133x.

Var Star: R Crv, VSX10671 , RA 12:19:38, Dec -19:15:22, Mag1 6.7, Mag2 14.4. 2015-04-26, C11, 55mm TV Plossl, 51x, Rating 3. Strongly reddish star, currently around ninth magnitude, forming a neat right angle triangle, at 50x, with an orange star and a copper coloured star.

Dbl: Algorab, δ Crv AB, RA 12:29:52, Dec -16:30:56, Mag1 3, Mag2 8.5, Sep 24.6". 2015-04-26, C11, 55mm TV Plossl, 51x, Rating 3. Brilliant white star, well separated, at 50x, from a much fainter companion, that sometimes seems to have a hint of yellow. Attractive, highly unequal pair. Algorab means "raven" in Arabic.

Multiple: STF1659, STAR20, Stargate AB, RA 12:35:44, Dec -12:01:30, Mag1 7.9, Mag2 8.3, Sep 27.5". AC, Mag1 7.9, Mag2 10.9, Sep 42.6". AD, Mag1 7.9, Mag2 9.9, Sep 189.6". AE, Mag1 7.9, Mag2 6.8, Sep 152.3". AF, Mag1 7.9, Mag2 6.6, Sep 208.3". 2015-04-27, C11, 55mm TV Plossl, 51x, Rating 5. "Stargate", triangle within a triangle, multiple star. Remarkable pattern. The inner triangle consists of two bright yellow stars, with a much fainter companion, forming an isosceles. That is enclosed in a much larger triangle, consisting of a deep yellow star, a yellow companion, and a substantially fainter component, again forming an isosceles, with the small triangle almost in the centre. Another asterism is visible just 50', as the crow flies, to the NE, STAR 21 or "Jaws", in Virgo.

Dbl: STF1669 AB, RA 12:41:16, Dec -13:00:50, Mag1 5.9, Mag2 5.9, Sep 5.2". 2015-04-27, C11, 55mm TV Plossl, 51x, Rating 4. Identical, bright, rich yellow stars, split by a hair at 50x. There is a super-wide, much fainter companion.

Asterism: Streicher 23 , RA 12:47:19, Dec -19:03:42, Size 32x44. 2015-04-27, C11, 55mm TV Plossl, 51x, Rating 4. Two lines of faint stars converge at a relatively bright, pale yellow star. Unremarkable asterism.

Dbl: S643 AB, RA 12:54:00, Dec -18:02:15, Mag1 7.1, Mag2 8.2, Sep 23.3". 2015-04-27, C11, 55mm TV Plossl, 51x, Rating 3. Mildly unequal, pair of pure white stars, well separated at 50x. They stand out well from a sparse field.

Great report Mike. Corvus is one of those constellations that observers tend to overlook because of it's low altitude.

And I thought my titles were bad.

Paul

Cheers Paul.

You have been exerting downward pressure on the quality of titles for some years, but new depths can occasionally be reached.

Excellent list as ever, Mike.

One of these days I will enter Corvus.
I have seen none of the above.

By the way, seeing you observed R Corvi, is it at its brightest right now? I am just wondering. Perhaps this is a true estimate of its magnitude.

Aubrey.

Thanks Aubrey, do take a look at the multiples in Corvus, they are worth checking out.

R Crv has a period of 317 days, and peaked a couple of months ago at magnitude 7.5 approx. You can check light curves for variable stars at www.aavso.org/lcg .

Mike