Zeta Lyrae. An Overlooked Double Star.

Hello again. For the fourth week in a row, there is no new image to post. We did have 3 hours of clear sky on Monday, but unfortunately 3 hours is not enough time to get a decent image especially in our area. Of course I did image a new object for those 3 hours, but like I say, its not enough time. One wonders when the weather forecast will say something different than mostly cloudy. Indeed, considering how much cloud we have in this country it might be better if the weather AI or actual people were to use different expressions than mostly cloudy. Let's face it this opens up some exciting ideas of grammer. They could start off with the not very dramatic "very cloudy" or perhaps "very, very cloudy". Moving up a gear we could then have "exceedingly cloudy" or "dramatically cloudy" followed by "overwhelmingly cloudy". Taking it a bit further we could then have "immensely cloudy" or "remarkably huge clouds". Or better still, to convey the real power of clouds we could go with "uncontrollably cloudy" or even better "crushingly immense clouds" which gives a real sense of being hemmed in by the forces of nature. As you can see the options are endless and really spices up the forecast. I mean, come on, it sounds a hell of a lot better than mostly cloudy..

Anyway, lets have a quick look at the double star in question, which is Zeta Lyrae. This double star is located in the northern constellation of Lyra the Harp.

As you can see on the star chart above, Zeta Lyrae is located somewhat to the left of the famous bright star, Vega. Obviously, Zeta Lyrae is not a single star but a multiple star system located approximately 158 light-years from our Sun. It consists of at least three stars and potentially more. The system contains two main stars, Zeta1 Lyrae and Zeta2 Lyrae, which form an extremely wide pair separated by an estimated 2,000 Astronomical Units, which is about seventy times as far from one another as Neptune is from the Sun. At this great distance, their mutual orbit takes millennia to complete, and it is estimated that their cycle may take as many as 50,000 years to complete!

Zeta Lyrae as imaged by me, the author. Taken on the 30th March 2024.

Zeta1 Lyrae, which is the larger of the stars in my image above, is a spectroscopic binary with a companion in a much closer orbit of just over four days. There are indications that Zeta2 Lyrae may also have a low-mass companion, suggesting a system potentially containing four stars. Zeta1 Lyrae is an Am star, a type of star with peculiar chemical properties. Its spectrum reveals unusual concentrations of metals like Iron (elements heavier than hydrogen and helium) in its outer layers. Zeta2 Lyrae is notable for its extremely rapid rotation, which is fast enough to cause the star to be deformed into a flattened oblate shape, with an equatorial bulge estimated to be 29% larger than its polar radius. As you can see, Zeta1 Lyrae is the brighter component, with an apparent visual magnitude of 4.37, making it visible to the naked eye under dark skies. Zeta2 Lyrae is somewhat fainter, with a visual magnitude of 5.74, and is barely visible to the naked eye in very dark skies. Zeta1 Lyrae was identified as a spectroscopic binary in 1905 by William Wallace Campbell and Heber Doust Curtis, based on photographic plates taken at the Lick Observatory. The first orbit for the system was calculated in 1910.

M57, the Ring Nebula. Image by me, the author.

So, a nice double star, and as I say in the header of this post, a rather overlooked double star because the object that everybody images in this constellation is the famous M57 the Ring Nebula. Also, double stars tend to be ignored by most imagers as they are not exciting or dramatic like nebulae. Personally, I am happy to image double stars as they only take an hour or so to get a good image. That's it from me this week and I hope to have something new soon if those "enormously mega huge cloud formations" ever recede for a while. Hope you have enjoyed this somewhat short-ish post. Take care and see you soon...