SERPENS CAUDA - The Grand Tour

[Tropo-Bob]

The weather looks good, so I have drafted more targets for tonight!

Serpens Cauda is tail section of the constellation generally referred to as Serpens. It is unusual because of it being split into 2 parts of the sky. I have previously reviewed the head (Serpens Caput).. Because of the split, my review of this half will shorter than normal.


The Main Stars:

Theta Serpentis (Ser). I know this pair as a fine double star, however, the literature refers to this as being a genuine triple system with the third related star being 7 arc minutes away.
https://en.wikipedia.org/wiki/Theta_Serpentis

Eta Serpentis (Ser). Eta is the process of evolving from a sub-giant to a giant star.
https://en.wikipedia.org/wiki/Eta_Serpentis

Nu Ser. This star marks the eastern most or beginning part of the Tail.
https://en.wikipedia.org/wiki/Nu_Serpentis


Objects of interest.

Gliese 710. This 9th Mag star is predicted to pass within 0.2 light years of Sol in less than 1.3 million years. This is expected to have major affects on the Oort Cloud.
https://en.wikipedia.org/wiki/Gliese_710

NGC 6604. An open cluster with nebula. This is often overlooked because of its prominent neighbours (M16 etc).
https://en.wikipedia.org/wiki/NGC_6604

IC 4756. A large open cluster. I could not find much on this one, but I do not know it, so I will have a look.
https://en.wikipedia.org/wiki/IC_4756


Messier Objects: M16.
Caldwell Objects: Nil

[Tropo-Bob]

I observed these last night using my Vixen ED 115mm with 24mm & 15mm EPs.


Objects of interest.

Gliese 710. This 9th Mag star is predicted to pass within 0.2 light years of Sol in less than 1.3 million years...
This is a faint star that is not even marked in the Uranometria 2000. For a star coming directly at us, I could not see any blue-shift at all. :D

NGC 6604. An open cluster with nebula. This is often overlooked because of its prominent neighbours (M16 etc).
I just saw a collection of stars without any nebula. It was a disappointment. Maybe there is more to it with a larger scope.

IC 4756. A large open cluster.
This was a very large group of stars that was very nicely framed with the 24mm Panoptic (37x). The group was strangely 'fenced in' by a group of 5 brighter stars. In 10x50 binoculars, the brighter stars overshadowed the cluster and I would not have noticed it. Well worth viewing through a small telescope, which has a wide field of view.


The Main Stars:

Theta Serpentis (Ser). I know this pair as a fine double star, however, the literature refers to this as being a genuine triple system with the third related star being 7 arc minutes away.
A wide pair of near equal, white stars that were well separated with only 37x. The third star is the nearest bright star. It does have an orange hue, but it is far away. If I had not read the literate, I would not have thought it was associated with the main pair.

Eta Serpentis (Ser). Eta is the process of evolving from a sub-giant to a giant star.
Ah, the vexing question of the colour. At times, colour appears to deepen as the magnification increases. At 37x, it appeared deep yellow, whereas at 60x, I would have described it as light orange. Or is there a different tint between a 24mm Panoptic and the 15mm Delite EP?

Nu Ser. This star marks the eastern most or beginning part of the Tail.
A white star at 37x. I was surprised to see it had a wide, fainter (aprox 4 magnitudes) companion. Haas calls it as 53 Ser, so I had failed to notice this beforehand. (Haas says, 4.3 & 9.4, separation 45.9").