Ring Nebula

From Scope F70076

Image:Cygnus.jpg

April 23, 2008. Tonight I saw my first deep sky object, the Ring Nebula or M57 in Lyra. The sky was cloudless, but visibility was still not good, with only a few brightest stars visible. The location where I am is also likely heavily light polluted, on light pollution map it is in the red pollution zone and is also near the sea, so that there is mostly a lot of moisture in the air. But it is still possible to find objects even in such light polluted skies.

First I noticed four stars in a pattern which resembled the tail of Cygnus. I looked from Linux Stellarium that Cygnus exactly supposed to be there where I saw it. Cygnus is also called the Northern Cross. Likely everyone can find the Big Dipper, a part of the Ursa Major, but at the opposite side of Polaris likely the most significant constellation is Cygnus, so one should be able to find it when looking at the direction where the Big Dipper is not visible. These four stars are like in the shape of a arrow head, with two more stars forming the tail of an arrow or the longer branch of the cross. Of these two stars only the farthest was faintly visible. Cygnus is an important constellation also because it is on the Milky Way, and indeed when I looked at that constellation with the 20mm eyepiece, a huge number of stars were visible, it is really beautiful to see so many stars through the telescope, these are only stars but it is really impressive to see them. At the top of the Northen Cross there is a bright star called Deneb, Deneb is one of the three brightest stars in the Northern hemisphere, which are mostly high in the sky, these are Arcturus, Vega and Deneb. Arcturus is the brightest, and Vega is the next brightest. All these three stars were visible.

I found Vega by the Stellarium map, near the constellation Cygnus, and thought that I should look at that star to check whether the stars which I saw are really what they supposed to be. Vega is a part of the constellation Lyra, which is a small constellation, and good in that most pairs of stars there are visible in the same field of view in the finder scope. There is a double star near Vega (Epsilon Lyrae), two stars with equal brightness, which should be visible in the finder scope together with Vega in the same field of view. The finder scope did show two stars near Vega, the other was more hazy one, so I thought that it should be the double star, but the finder scope couldn't resolve it. Then I moved that star into the center of the crosshair, and looked through the 20mm eyepiece, I clearly saw two stars with equal brightness, and then I knew that the bright star which I saw was indeed Vega.

So I moved ahead with the finder scope from Vega to Zeta Lyrae, and from there to Delta Lyrae. In the 20mm eyepiece I saw that this was indeed a double double star, so it was verified that it was Delta Lyrae. From Delta Lyrae I moved to Gamma Lyrae (Sulafat), and cleary saw the other side of the Lyra trapezium, Gamma Lyrae and Beta Lyrae, in the same field of view. Almost exactly in the middle of these two stars, slightly outside the trapezium, is the Ring Nebula. I moved the point where the Ring Nebula supposed to be into the center of the crosshair, it even seemed to me that I noticed some hint of some object there in the finder scope, but nothing was clearly visible there. It is not a good idea to find something "in the middle", because the location is not then well determined, and it is not possible to move to that location precisely enough. The Ring Nebula is in a way an exception, because it is located so near to Sheliak (Beta Lyrae) that it can be seen in the field of view of the 20mm eyepiece together with that star. There are also two less than magnitude 9 stars near the Ring Nebula which can be seen through the eyepiece, but I found no patterns of stars which could help to locate the Ring Nebula more precisely.

Then I looked into the 20mm eyepiece, and after some slight moving around I saw a hazy patch, which was hazy in spite that small stars around it were focused to almost a point. The brighter stars never focus to a point and are like sparkles with the light polluted skies, ideally they should be round with diffraction rings around them. I looked into the same area with the 12.5mm eyepiece with and without the 2x Barlow lens, and with the 4mm eyepiece, focusing the stars every time. The 4mm eyepiece didn't give much, looking through it seemed like looking through a keyhole, it may be good for looking at some bright objects like planets, but it cannot show anyhow better the hazy patches like nebulae and galaxies. The 2x Barlow lens couldn't make anything better either. The object looked the best through the 12.5mm eyepiece (56x magnification). It was quite small, but clearly hazy, or nebulous. I saw that it was a round hazy patch, but I really couldn't see that it had a round shape, maybe at some moments I noticed some hint of it, but didn't really see that at all.

This is likely what one can see with the light polluted skies and bad visibility, what the condition is unfortunately most of the time. It is said that one can see more after some more practice of seeing the deep sky objects, because the brain would learn to obtain more from what you see. I think that at least somewhat this should be true, but I describe here the experience of a beginner, and a beginner certainly has no experience of looking at the deep sky objects for hundrieds of hours. A telescope with a larger aperture and therefore with greater light gathering power would certainly show more, but with clear skies this telescope would certainly show the Ring Nebula quite nicely.

Did I see any color? Well, I didn't really see what I could call color on any stars, neither on the Ring Nebula, they are all a kind of blue, but the light of different objects certainly has a different character, one can see this but it cannot be exactly called color. This light is though still very impressive, and faint differences of it are beautiful as well. I would finally say that there really is a kind of magic in what you see by looking at the night sky through telescope, in spite that I didn't see that much this time, I would like to do that more.

And the other thing which I found was that with these light polluted skies, any smaller telescope than this 76mm one does not have enough power to show anything, as even this telescope had barely enough power to show a hardly visible faint patch of light where the Ring Nebula is, so faint that it is certain that nothing were visible there through a 50mm scope, in the conditions of that visibility and light pollution which likely is the condition most of the time. Well and, a 60mm telescope and a wobbly tripod would have been as bad. Don't even try to use any smaller telescope with the light polluted skies, this is nothing bout a waste of time, because these are not good enough instruments to find anything in these conditions. This is clearly a minimal telescope which makes sense to buy, I have no doubt in this now, but it is a useful instrument still.

The Ring Nebula was discovered by Antoine Darquier de Pellepoix in 1779, who described it as a "dull nebula, but perfectly outlined; as large as Jupiter and looks like a fading planet".

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