Lying beyond the glare of the stellar behemoth Deneb in the constellation of Cygnus, making up a glorious cosmic quartet, sits Omicron-1 and Omicron-2 Cygni. An orange K3Ib super-giant, Omicron-2 is an Algol type variable star — an eclipsing binary with a smaller, but brighter short period companion. By sheer coincidence Omicron-1 is also an Algol variable belonging to the orange spectrum — a K2II giant to be precise — but other than their apparent resemblance there is no physical relationship between these “twin” stars.
Sitting close to Omicron-1 can be found 30 Cygni and HIP 99676 also known as 31 Cygni b. The former is a white to blue white A5III giant while the latter is a blue white B9 star with no clear luminosity grading. Again, like Omicron-2, there is no association — except for a common optical axis within a populous field of the Milky Way — between these stars and Omicron-1.
The 25×100 binoculars easily revealed the orange hues of Omicron-1 and 2 while 30 Cygni appeared close to it’s spectral classification. HIP 99676 on the other hand posed a slight puzzle as it appeared a greenish white. Regardless this proved to be a beautiful grouping of stars which are well worth a look if you have the time to spare during an observing session.
Tags: 30 Cygni, Cygnus, HIP 99676, Omicron-1 Cygni, Omicron-2 Cygni, Strathspey 25x100