How can I be sure I saw what i thought I saw.

[Astro Imp]

Last night I was looking around at some doubles and star clusters before the moon rose. I did't look at the fainter DSOs as the light pollution was not good. I had a look at M45 and there was definitely haze around some of the stars. Could this be the nebulosity associated with this object or was the cause something else? At the time M45 was high in the sky. I'm doubting my observation as I've never noticed this before and would not expect to see this under the conditions last night.

[John]

I've noticed that apparent nebulosity around some members of the group quite a few times over the years. I put it down as the reflection nebulae, the Merope Nebula.

It's not consistently visible though.

[Astro Imp]

Thanks John, it's just I wasn't expecting to see it and have never noticed it before.

[Ben the Ignorant]

10 minutes ago, Astro Imp said:

Thanks John, it's just I wasn't expecting to see it and have never noticed it before.

Check the humidity rate for last night, you'll probably find it was lower than usual.

[kippford]

Could have been a puddy tat.?

[Carbon Brush]

First time I saw it, I thought it was a grotty eyepiece. Then later realised I was looking at glowing gas.

I think it was probably an 8" newt as this was my first 'proper' scope.

Or the first scope with enough light gather to show me the glow.

David.

[Stu]

I would think it unlikely if the light pollution was such that it wasn't worth going after fainter DSOs.

When I've seen the nebulosity before it has usually been a fogged up eyepiece or objective . I guess you would need to map out where you saw it to see whether it was real or not.

In theory it should need transparent and dark skies to spot.

 

[cloudsweeper]

You were probably right, Alan.  I've noticed the reflection nebs around Alcyone, Electra, Maia, and Merope.  They were all very faint, but I recorded that Alcyone's nebulosity was about the clearest of the fuzzy patches.

Doug.

 

[Mark at Beaufort]

I have seen the nebulosity around the star Merope but not much of the other areas. As Stu stated above in the past I thought I was seeing it but it was the eyepiece fogging up. The attached photo shows the area. The best way to identify the area is check out star 24(Alcyone) which has a trail of stars beneath it and star 23 (Merope) and just look at this area. If you see nebulosity solely around Merope you have bagged it.

[mikeDnight]

Hi Alan,

If you keep on observing the Pleiades for an extended period, you may notice the nebulosity extend beyond the cluster. Sometimes it becomes more obvious if you gently nudge the scope which may help you to detect subtle nebulosity away from the stars themselves. You might also like to check stars around the pole which you'll likely find do not show the nebulous glow around them. Good dark adaption works wonders, so try to keep stray light from your local surroundings from catching your eye. I use a black blanket to cover my head and focuser, and spend quite some time on each object so I can really study what my little scope is capable of revealing. 

[jetstream]

1 hour ago, Astro Imp said:

Last night I was looking around at some doubles and star clusters before the moon rose. I did't look at the fainter DSOs as the light pollution was not good. I had a look at M45 and there was definitely haze around some of the stars. Could this be the nebulosity associated with this object or was the cause something else? At the time M45 was high in the sky. I'm doubting my observation as I've never noticed this before and would not expect to see this under the conditions last night.

A good way to tell is noticing if there were any of the "glows"  not quite round or if one was bigger than the rest. Typically haze will make all the glows look pretty much the same.

[Astro Imp]

18 minutes ago, Stu said:

When I've seen the nebulosity before it has usually been a fogged up eyepiece or objective

From reading the very informative posts I think this is the most likely explanation.
Thank you to all who have posted.

[Astro Imp]

3 minutes ago, Charic said:

.Not sure Astro Imp, but can you trust us, to tell you, what you really think you thought you saw, when in-fact what you  really saw was real................ or was it? ?

Stop it, you're making my head hurt. ?

[Alan White]

Alan,

This has been a point of chatter with fellow observers at my astro club, the majority do not think you can see anything.
I am convinced on good nights I have seen as per @mikeDnight sketch or very similar, but did I really see it? Well I think I did.

[Stu]

14 minutes ago, Alan White said:

I am convinced on good nights I have seen as per @mikeDnight sketch or very similar, but did I really see it? Well I think I did.

Alan, on good dark nights I'm sure it is possible, so if Astro Imp had described a cracking night with good transparency I would think it quite likely. With skies that made faint DSOs not worth it, it makes me more doubtful and more likely that other factors were at play.

The only way to really prove it is with another observation, noting the position of the nebula as per Mark and Gerry's posts.

I'm sure it is an observable effect with the right conditions, so if you have seen it, I believe you

[Size9Hex]

I’ve caught the Pleiades nebula a couple of times from a NELM 6.5 dark site, but at home (mag 5.5) I’ve never convinced myself it’s anything other than stray glow from the stars. The Merope nebula is the only one I’ve definitely ticked. It’s a large curved sweep of light to one side of Merope and quite different from the symmetrical glow of stray light.

[Astro Imp]

2 minutes ago, Size9Hex said:

symmetrical glow of stray light.

The more I think about it the more I become convinced this is what I saw.

[Size9Hex]

8 minutes ago, Astro Imp said:

The more I think about it the more I become convinced this is what I saw.

I’ve spent quite a bit of time studying it from home before concluding the same thing. ?

I think it’s a target which doesn’t stand up to much light pollution at all and unlike some objects it doesn’t seem you can bludgeon it with filters or aperture. My most memorable view of it was in 10x50 binos! Low power really helps with the Merope nebula.

[Les Ewan]

I've tried for decades to see nebulosity around  Merope visually  and failed ,and I  stay in a fairly dark site. Their has been times I think I've seen it but I think the best practice  is that if your unsure about an observation it is to best to discount it.

[Moonshane]

I agree with Les. If you are not sure, keep returning to the object over a period of time until you are sure or until you conclude it's not visible with your conditions or equipment. Otherwise, what's the point in recording it? You are really only cheating yourself. Plus as hinted at above, it's often the case that objects appear or disappear at will according to conditions 

[Ben the Ignorant]

Excerpt from Burnham's Celestial Handbook, with a mention of "a stain of fog" resembling "a breath on a mirror", interesting comparison with breath on an eyepiece lens, but also the fact it can be seen with only 2 inches of aperture. So there's nothing difficult in believing you saw it with your 8-inch dob, Alan.

Another interesting point is it disappears when the scope is too large (18-inch Dearborn refractor), surely because glare from the star becomes too strong.

[Astro Imp]

4 hours ago, Moonshane said:

I agree with Les. If you are not sure, keep returning to the object over a period of time until you are sure or until you conclude it's not visible with your conditions or equipment. Otherwise, what's the point in recording it? You are really only cheating yourself. Plus as hinted at above, it's often the case that objects appear or disappear at will according to conditions 

Thanks Shane, I always make sure when recording sightings of objects, as you rightly say there is no point in observing otherwise. This hobby isn't a competition but an exploration of the sky and it's treasures. Returning to objects for a second/third or more view has always been part of my routine.

[Moonshane]

One interesting aspect of observing faint objects is that they are often so easy to detect after you see them the first time. In my experience, the nebulosity around M45 has always proved impossible. That said, the comment from Burnham above is perhaps important as I generally observe from dark skies with my 16" dob. The only time I felt I was 'seeing something' was with a 100mm f7 ED frac from the same site. Maybe I was! I'll certainly return to this object on a regular basis anyway as it's so lovely.

[John]

I've noticed this nebulosity on numerous occasions but not every time that I observe this group as I said in my post above. It's something that I took for granted really and never thought it a major challenge but rather nebulosity that certain conditions rendered visible.

 

[Stu]

1 minute ago, John said:

I've noticed this nebulosity on numerous occasions but not every time that I observe this group as I said in my post above. It's something that I took for granted really and never thought it a major challenge but rather nebulosity that certain conditions rendered visible.

 

I suspect related to good transparency as much as anything else perhaps John?