Pure Magic

We all have as observers different reasons why we track down different objects. Sometimes it's because this or that star is intrinsically interesting, or because it possesses one or more superlative (the biggest, the closest, the oldest, the furthest, etc.). Sometimes it's because the object is bright and splashy, and fills one's field of view with all sorts of complexities.

30 Cygni off to the upper left - 31 Cygni A and B off to the lower right

But every now and then we check out this or that deep sky object because.. well, darn it, because it's beautiful! Such is the case for Omicron Cygni. It's not just that their arrangement is aesthetically pleasing - their brilliant colors (bright gold and electric blue) rival those of the more famous (and nearby) Albereo.

Another view of 30/31 Cygni, showing off their colors

Now Omicron Cygni isone of the more confusing appellations up there, because several stars in Cygnus all go by that  label. Much better to use the Flamsteed designations 30, 31, and 32 Cygni, all of which make up "Omicron Cygni". Confused? So am I.

But there's more to Omicron Cygni than a pretty picture (although that's quite enough). The stars are interesting in their own right. 30 Cygni is a blue-white giant star, 610 light years distant, shining with the radiance of 324 Suns, making it a magnitude 4.83 star to our view. Nearby (visually, at least) 31 Cygni is an easily splittable binary. Despite its apparent nearness to 30 Cygni, the 31 Cygni system is 880 light years from our Solar System, so the 2 are actually separated by 270 light years. 31 Cygni's A component is an orange supergiant, 4,300 times brighter and 200 times the size of our Sun. Its dimmer B companion appears to different observers as either bright blue or "dirty" white. The three stars, although in actuality quite distant from each other, make up an attractive apparent triple star due to a chance line of sight alignment.

32 Cygni at upper left, 30 and 31 at bottom right

Meanwhile, 32 Cygni sits off about 1 degree to the north, completing the view through any eyepiece with a moderately wide field of view. At 1,100 light years away, it is the most distant of the "Omicron" stars in Cygnus. 32 Cygni is a spectrographic binary. (Its components cannot be separated visually.) The A component of this system shines with a luminosity of 6,600 Suns and is bright orange. Meanwhile, its poor B companion star has to make do with only 300 times the Sun's luminosity, and by itself would be a blue-white main sequence star. The 2 components make up an eclipsing binary, similar to Algol over in Perseus. Because the plane of the stars' orbits is precisely aligned with our line of sight, we can spectrographically study the solar wind of the primary star during each eclipse. From these observations, astronomers have concluded that 32 Cygni A is losing an incredible full stellar mass every 77 million years. Wow.

By the way, the colors in the above image do not do justice to the glorious view one gets through the eyepiece. I never fail to spend a minute or three just drinking in the view whenever Cygnus is high in the sky. Don't miss it this summer!