Posts Tagged ‘NGC 6960/6992/6995’

Coronas and Clusters

The moon was out in force last night (11.10.08) which put paid to half of my DSO search list, but more about that in a moment. I spent the first half of the evening imaging the moon. I wasn’t trying to go for a classic lunar shot per se but a more scenic image of the moon as it passed through the trees at the front of the house. I had the foresight to take a dark frame, but I think that there is still some noise in there that could be processed out. I had taken a number of pictures at F/Stops between 5.6, 8 and 11 as well as shutter speeds between 1/400 and 2 seconds. Best of a bad bunch, the overexposed image above was shot using an F/Stop of 8 at 70mm and an ISO of 400 with a shutter speed of 1/400. A lower ISO and bracketing might be the order of the day next time around. All in all, it’s still a nice image, but the thing that I like about this shot is the fact that I managed (unwittingly I might add) to capture a ‘corona’ around the moon albeit a mild one.

By early Sunday morning I turned my attention to the DSO search. First up was The North America Nebula NGC 7000, The Pelican Nebula IC 5070 and the Veil Nebula NGC 6960, 6992 and 6995 in Cygnus as well as M56 and M57 in Lyra - then I realised that I had zero chance of seeing anything in this part of the sky as the moon was now shinning low in the west.

I turned eastwards determined to carry on my DSO hunt in spite of the moon. Here I was looking for M36, M37 and M38 in the constellation Auriga. These open clusters are really something special - at 25 million years old, M36 is the youngest of the group. Lying 4,100 light years from the Earth, the stars here cover an area of around 14 light years. With a distance of up to 4,600 light years, M37 looks to be the oldest of the group with an age of 300 million years. This cluster contains over 500 stars with at least a dozen of them red giants. At around 220 million years, M38 is the second oldest of the group and lies 4,200 light years away spanning at least 25 light years. As views go, this is a fantastic part of the sky and one I’ll be returning to a lot more in the future.

Traveling south eastwards, I pointed my 25×100 binoculars at what is probably the most famous nebula in the night sky - M42/M43. Otherwise known as the Orion Nebula. This is a spectacular object to observe, and even under my light polluted sky the nebula was visible with the naked eye. Through the 25×100s M42/M43 showed up as a pale blue smear against the night. The nebula covers an area of around 24 light years and is generally considered to be the closest area of mass star formation to Earth. A really wondrous sight.

Last on my list was Collinder 50 i.e. The Hyades in Taurus. This is the nearest open cluster to Earth lying only 151 light years away and containing 300 to 400 stars that all share a commonality. This part of the sky really is best viewed through a pair of 10×50 binoculars so you can savor the cluster in it’s entirety.

By about 02:30 UT I decided to call it quits. Having spent most of Saturday daytime not feeling too well I decided that discretion really was the better part of valor.

Not a Cloud in Sight

Saturday night was probably the best observing session that I have had in a while. The seeing was 5/5 while the sky transparency was in the region of 4/5, so not great. As always, my observing program begins with a look at the moons Jupiter. On show were from left to right Ganymede, Io and Europa. Callisto should have been about 8.7 arc minutes west from the centre of Jupiter. I’ve written it off as being down to light pollution and reduced sky transparency, but this is the second time I have failed to resolve Callisto through my 25×100 binoculars.

Moving on from Jupiter, I turned my attention to the constellation of Sagittarius, or what I could see of it from my position. My interest here, was to observe four Messier objects: M25, M24, M18 and M17. Using the 25×100s’ I successfully located M25, an open cluster of stars 2000 light years away from Earth. I wanted to clarify my find, so turned to my trusty 10×50s’ binoculars. The view of the cluster through the 7° FOV was a delightful sight, but I’m sure it would probably have been better in darker surroundings.

Although M24 is just west of M25, locating it proved a little more difficult. Also known as The Sagittarius Star Cloud, M24 is a pseudo cluster of stars some 600 light years wide. While I had placed the cluster It was extremely difficult to resolve it through the orange LP haze. The myriad of stars that were visible still delivered a beautiful sight all the same.

While I was searching for M24 a surprise satellite shot into my FOV. Now I don’t normally set out to track satellites, but a few have sprung up on me during my observations over the past month so I decided to do some checking up to find out which satellite this was. The Lacrosse 4 Rocket is the only one that fits in with my time frame and azimuth coordinates. As I’m not adept at tracking satellites I can’t be too sure how reliably this information compares with my observation.

Returning to my Messier search I began looking for M18, an open cluster not too far above M24 which also proved a little conspicuous. None the less, the view through my 10×50s’ was still a rewarding one. However, the real crown jewel of the evening was to be M17, The Omega Nebula.

A H II emission nebula between 5000 and 6000 light years from Earth and 15 light years in diameter, M17 is a fantastic sight. Even although it looked like a dim grey(ish) white smudge against the night sky through my 10×50s’ it is amazing to think that the gas in this nebula is around 800 solar masses.

The final Messier object on my list was M16, The Eagle Nebula. Technically, this open cluster is in the constellation Serpens, but it lies pretty close to The Omega Nebula so I thought I’d include it in my observations. Surrounded by a H II region known as IC 4703, the nebula lies a staggering 7000 light years away and is truly fantastic to behold.

Taking a much needed break I eventually moved my observations towards Cygnus and six objects, a mixture of stars and DSOs’. Deneb, NGC 7000, IC 5070, NGC 6960/6992/6995, Albireo and M56 in Lyra.

Turning the 25×100s’ on Deneb, a white super giant and one of the most luminous stars known, it was clear to see that it stood up to it’s reputation. The depth of stars that also surrounded this monster star was enumerable and breathtaking. From here I worked my way upwards towards NGC 7000 otherwise known as The North America Nebula 1.

Another emission nebula, distances to NGC 7000 are not precisely known. If Deneb is responsible for ionizing the gas in the nebula, estimates would place it at about 1800 light years away with a diameter of around 100 light years. The depth of stars in this area of the sky was unbelievable and completely blew me away, but unfortunately, due to transparency conditions I could’nt make out any nebulosity. My luck was also out with IC 5070 or The Pelican Nebula as it is better known. Disappointments aside, this is a truly brethtaking part of the sky and I felt as though I could have gazed upon it for hours.

Moving down Cygnus, my next target was The Veil Nebula i.e. NGC 6960/6992/6995. The remenants of an ancient supernova that exploded somewhere between 5000 to 8000 years ago, the nebula is all that remains. Though actual distances to this DSO are not known, estimates place the nebula between 1,400 and 2,600 light years away. I wasn’t overly optimistic that I could nail this faint DSO down, and how right I was. I quickly gave up the search here as I realized that my efforts would be fruitless.

My second last stop was the double star Albireo. At a distance of 380 light years from Earth, Albireo consists of a brighter yellow star and a faint blue companion. My 25×100s’ split the two stars reasonably well and I could pick out the contrasted colours of the two stars. From here the final stop was the globular cluster M56 in Lyra.

By this point my binoculars were beginning to fog up, suffice to say M56 remained quite elusive. Rather than continue to search through fogged up binoculars I broke out my 10×50s’ and reacquainted myself with some old friends while making a new one.

The Pleiades were quite high in the south east sky and I couldn’t resist a peek. Without waxing lyrical, this is one of the best views in the night sky and a simply stunning sight.

From here I moved on to M31, The Andromeda Galaxy and nearly broke my neck looking at it. Sitting almost at the zenith, this was probably one of the best views I have ever gotten of it through a pair of binoculars. Moving down from the constellation Andromeda, I decided to try my luck with the Triangulum Galaxy M33. I swept the sky a few times from Mirach in Andromeda to αTrianguli and that’s when it suddenly resolved right there in my binoculars like magic. A pale, distant ellipsoid lying some 2.9 million light years away.

After searching for this DSO earlier in the month, this was quite an achievement for me. Undoubtedly limited local light pollution at 02:30 UT in the morning was a big help. At this point, the cold began to set in, so I decided to content myself with my observational successes and call it a night.

  1. On an interesting note, while I was repositioning the binoculars on my way to NGC 7000, a small, faint meteorite passed through Lyra towards the north, just within my field of vision. At a guess I’d say it had an entrance and disappearance arc of maybe 20° to 30° with a small short tail.