What Constitutes “Seen”?

[Bill Weir]

Recently I’ve been part of a debate about the concept of what constitutes seeing an object. The object in question is the Abell GC 2065 and a preported observation using a 12.5” scope. The observers blog and the observation is here and it’s the last on the page. http://s00639.blogspot.com/2018/05/a...-ngc-5897.html
I’m inclined to say the object was observed even though it was minimal. He did the best he could with the tools and conditions he had available.

An observation is always limited in one way or another. Sometimes with a very low surface brightness face on galaxy it may only be the core that’s visible. With large supernova remnants maybe it’s only a few of the brighter strands detected. With a galaxy cluster, observing all of the galaxies involve is usually impossible and is totally dependent on sky conditions and aperture.

So that’s my question, how much of an object needs to be seen before you consider it an observed object. I guess you could add to this do you require a repeat observation to truly verify the observation. Adding a sketch to the observation to me is the icing on the cake.

Bill

[Bill Weir]

I see the above link doesn’t seem to work so trying again.
http://s00639.blogspot.com/2018/05/abell-1656-abell-2065-ngc-4676-ngc-5897.html

Bill

[Norman]

Hello Bill,

in my opinion already the smallest amount of a catch is a catch. And each observation is a result - even when haven´t seen anything. When you travel for holiday to a foreign country - you have been there. Saying having been there does not mean that you pretend to know the whole country...

CS
Norman

[Mark McCarthy]

Agree with Norman and yourself; a marginal observation is still an observation.

BTW thanks for pointing out the blog; the author writes beautifully and enthusiastically! Google Translate to the rescue!

[Ivan Maly]

That's a fine observation. It's an accurate enough sketch to verify the field. Stars down to at least Vm 15.5, what you'd expect from the conditions and a practiced observer. If I'd observed 1 galaxy as separate, and an unresolved pair, I'd call it an observation of the cluster, although that's the bare minimum. If it's just one, I'd call it "observation of galaxy X marking cluster Y". (Which is exactly the most frequent result if you just go after the Abells.) This fellow is very thorough, judging by his blog. (Or hers, I didn't read enough.)

Incidentally, I agree that a sketch is the icing on the cake. As you go past a certain point even in the NGC with a transportable scope, you can't be sure you are looking at the intended target without verifying a sketch, if you stay strictly visual.

[Dragan]

I agree with the above responses. The slightest hint is an observation. To me. It's really a matter of my level of confidence in seeing it. I try not to BS myself but if I feel positive at all that I saw something or anything at all, it's a positive observation. If I have doubt, I leave it as a negative observation and try to come back to it.

If I'm by myself, I'll try to make as accurate a note as possible about what I saw and when I come back to it another night, I'll confer to them and see if my observations match.

If I'm with someone, I just ask for confirmation.