Double Stars & A Little Bit More

Anyone reading this blog will know that I am slowly discovering the various double stars in Ursa Minor and this post details the next three stars in my adventure, STF 1958, STF 2134 & STF 2299. However, the same night that I observed these stars I also decided to explore a few other night sky objects such as the Garnet Star, Foxhead Cluster (NGC 6819), Caldwell 1 & NGC 7160. The locations of all these targets are shown below.

STF 1958 (SAO 16749)
RA: 15 29 24.12 Dec: +67 12 16.0
Magnitudes: 9.63, 9.97
Separation: 29.7”
Position Angle: 338°

The first of the double stars of the night and to be honest it wasn't that impressive with me not actually noticing the secondary star until I used averted vision even with the decent separation. As my night vision improved I managed to look at it directly but to be honest both the stars just looked a dim white colour.

STF 2134 (HIP 83092 / SAO 8679)
RA: 16 58 44.10 Dec: +76 06 33.0
Magnitudes: 9.43, 10.22
Separation: 45.8”
Position Angle: 144°

As my night vision was better by now I could see both the primary and secondary straight off without needing any averted vision, this was of course helped by the decent amount of separation. As with the previous double, both stars appeared white although the difference in magnitudes made for a greater level of contrast between them.

STF 2299 (SAO 2933)
RA: 17 38 55.61 Dec: +84 02 42.9
Magnitudes: 9.46, 9.67
Separation: 33.5”
Position Angle: 124°

My final double of the night and another uninspiring target with both stars once again coming across as white and easily separated. I appear to be at the bottom of the barrel when it comes to interesting doubles in Ursa Minor but I will keep going until I think I have reached the limit of my current scope.

Garnet Star / Mu Cephei (HIP 107259 / SAO 33693)
RA: 21 43 30.46 Dec: +58 46 48.17
Magnitude: 4.08

The Garnet Star is a red supergiant in the Cepheus constellation and is one of the largest and most luminous stars known in the Milky Way. Its name comes from the fact that it Herschel noted it had a Garnet Red colouring. I have to admit it is a lovely sight to look at which a lovely red colour that clearly comes through. After looking at plenty of white coloured doubles this evening it was nice to see something showing a bit of colour. It reminded me a little bit of the star La Superba in Canes Venatici which also has a clear red colouring.

NGC 6819 / Foxhead Cluster
RA: 19 41 18 Dec: +40 11 00
Type: Open Cluster
Magnitude: 7.3

NGC 6819 is located around 7,200 light years away in the Cygnus constellation. It is called the Foxhead Cluster because the brighter star form a triangular shape which is supposedly like the head of fox.

I have to admit that I struggled to see much from my back garden and I could make out maybe 4-5 stars at most which was very disappointing. However, even with this limited number of stars I could see that there was a vague "V" shape to them which helped confirm I was in the right location. Another interesting thing I noted was that surrounding this small cluster was another set of brighter stars which also formed a triangular shape.

Caldwell 1
RA: 00 48 Dec: +85 15
Type: Open Cluster
Magnitude: 8.1

Caldwell 1, also know as NGC 188 is an open cluster in the Cepheus constellation about 5,000 light years away. Unlike most open clusters that drift apart after a few million years because of the gravitational interaction of our galaxy, NGC 188 lies far above the plane of the galaxy and is one of the most ancient of open clusters known, at approximately 5 billion years old.

The light pollution from Grangemouth Oil Refinery to the North of my home meant there was a fair change I wouldn't see anything but I could still make out a barely perceivable patch of light in the sky. For this cluster I really need to use a bigger aperture although I might be able to get more from a darker site as well. Either way, the most disappointing of the night but this probably should have been expected given a 5 Inch telescope was always going to be pushing it due to low surface brightness etc.

NGC 7160
RA: 21 53 40 Dec: +62 36 12
Type: Open Cluster
Magnitude: 6.1

NGC 7160 is located around 2,600 light years away in the Cepheus constellation. This was probably my favourite Open Cluster of the night because it was pretty clear to see with about 9 stars being visible. The shape itself was quite interesting to behold and to me it looked almost like a tadpole.

It was quite a compact cluster so I am not sure how much more I would be able to resolve at a darker site but I still suspect I will be back to it in the future as it was quite nice to see.