What is this ??

[TimLeigh]

 

Hi,

My main interest is nightscapes with my dslr, but I thought I would try a bit of other stuff from my east midlands UK town back yard over the winter, just for a chance to do some night photography. I was looking to photograph the Andromeda galaxy, and came across this, which I thought was a star, somewhere in the general direction of Andromeda . A 20s exposure burns it out, but 8s shows detail – it was only by chance I took a couple of 8s shots.

It seems to be static with respect to the star background, have a bright core, with surrounding uneven rings, and a possible jet from one side. I only noticed the details when I looked more closely at the images the next day, hence the rather vague positioning below. Any bright ideas ??

 

Date 5.2.22. Time: 8.00 – 8-30pm   Somewhere around a bearing of 280degrees, elevation of around 45 to 60 degrees, from a position with latitude 52 degrees and longitude -1.4 degrees. (Leicestershire, UK)

Canon 600D, 500mm mirror lens, f8  1600iso. Ioptron SkyTracker.

 

Picture 1:  5 stacked images each of 20s.Processed.

Picture 2: Single image of 8s. Unprocessed. Converted to JPG.

Picture 3: Two stacked images each 8s (one of which is picture 2). Processed

 

Its probably very obvious, but I am at an early stage with all this, so don't be too brutal 😏

Tim

 

 

[ApophisAstros]

Roger

[TimLeigh]

Thanks for this. Spot on regarding position relative to nearby stars. It must be Almach. 

 

Any thoughts why my images seem to show some sort of structure, with rings, and a jet ?

 

The jet is also visible on all the 20s exposures. The "rings" seem to be there in the 8s RAW unprocessed files as far as I can see. The first image below is cropped from an 8s unprocessed image. The second is a 100% crop from a 20s unprocessed image - not bad for my quality of equipment, and a 500mm lens, though the star trails are very obvious.

 

Are these "structures" really there, do you think, or are they some sort of  a result of my gear - which is being pushed to its limit ?

[TerryMcK]

It will be an artefact created by your optics. 

[TimLeigh]

Thanks for your help with this. Fascinating.

I understand what you are saying about my optics – they are certainly not the best, though I have found the Tamron 500mm mirror to be generally pretty reliable as long as the focus is spot on !

I have found a few images here: Almach (Gamma Andromedae): Star Type, Facts, Name, Location, Constellation | Star Facts (star-facts.com)

And here: Almach - γ1 Andromedae (gamma1 Andromedae) - Star in Andromeda | TheSkyLive.com

And here: Gamma Andromedae (skyledge.net)

Some of these images are not a million miles away from what mine hint at about Almach: a double (actually quadruple it seems) star with some sort of outer atmosphere with variations in density. In other words, the jet and rings in my image are the result of the optics, yes,  but have some basis in reality, and I also wonder about the software interpretations of the RAW files.

Thanks again,

Tim

[paul]

Your image shows that camera lens are great for wide field views (constellations, milky way, bright comets etc ) but begin to show their limitations when you look too closely. Its asking a lot of a practical (affordable)  compact camera lens to give you aberration free stars across the frame.

 

By the way, the diameter of the lens determines how much small detail you can see. Bigger gives finer details. Its an interesting fact of physics that the bigger the aperture of your lens the smaller the stars will appear in the image🙂

 

[TimLeigh]

Thanks Paul,

I can indeed see that venturing into deep sky stuff is a different ball game to the one I usually play, and I will probably stick to wide field stuff - until something else a tad mysterious comes along.😏.

My usual lenses are f2.8 or even f2 to get plenty of light in, but I understand what you mean about the diffraction effects of smaller apertures, and the f8 of my telephoto has a built in problem with the resolution of detail.

 

An enjoyable thread, and I appreciate the experience obviously abroad in the forum. 

Tim

[Josie]

That’s interesting. I have a similar photo of a star surrounded by what looks like a musical clef. At first I thought I had bumped my tripod, but all the other stars are sharp. It hasn’t happened since, and I’ve taken many hundreds of shots after this one. Obviously, I’ve found proof that the Jetsons do exist! 

 

Edited February 20, 2022 by Josie

[paul]

4 hours ago, Josie said:

That’s interesting. I have a similar photo of a star surrounded by what looks like a musical clef. At first I thought I had bumped my tripod, but all the other stars are sharp. It hasn’t happened since, and I’ve taken many hundreds of shots after this one. Obviously, I’ve found proof that the Jetsons do exist! 

 

I think your first thought is correct, that star is so much brighter than the others and the trail is faint. Plus I think if that was the Jetsons they are on the biggest road trip ever😂

[TimLeigh]

If the tripod was bumped, it could sway to one side, then back to the other, and could well give a slight increased brightness at either end where it is travelling slowest and coming to a stop (simple harmonic motion of a sort). Your shape is indeed slightly brighter at either extreme, so I am with the bumped and slightly swaying tripod theory. Nice.