Archive for September, 2008

A Small Slice of Sunday Night

Sunday (28.09.08) night served up another cloudless sky so I made the most of it and headed out with the 25×100s’ for an unplanned observing session. Jupiter as always was hanging low in the south west and was the first target. While there were no clouds to contend with, the sky transparency was predictably murky - I’d say 3/5. The seeing wasn’t bad and I’d probably grade it around 4/5 but the conditions lacked the clarity of Saturday evening.

Despite the conditions, I managed a good observation of Jupiter with Ganymede, Io and Callisto also visible. Europa was occluded by Jupiter so there was no flim-flam observing this time around.

While I was observing, another satellite flew into my FOV from the west on a south west heading just below Jupiter. Despite my best efforts at finding out, I have absolutely no idea what satellite this was.

I decided to return to Sagittarius and the handful of DSOs’ that I had managed to net on Saturday night. Disappearing slowly behind the roof tops, M25 was just visible through a soup of orange light pollution and atmospheric moisture. From here I tried to refine my observation of M24 and after staring at the same patch of sky for five minutes I barely resolved the faint open cluster. While M24 proved difficult, M18 was a no show which if I’m honest I kind of suspected anyway, so there was no disappointment there. In contrast, The Omega Nebula was clearly visible and looked just as fantastic as it did on my first viewing. M16 was also observable, but it looks far better when a low power is used. This aside, it was still an enjoyable and pleasing sight through the 25×100s’.

Within the half hour that I was out for, the sky conditions had began to degrade rapidly as clouds started to roll in from the west and the north west. Realising that observing was soon going to become a thankless task, I decided to end nigt there and wrap up the gear.

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.

The Final Diagnosis

An exceptionally clear evening on Monday night (22.09.08) meant that another, albeit short observing session was on the cards. As always, the first port of call was a view of Jupiter through my 25×100s’. This time, observing was much easier than my previous outing as Jupiter was not obscured by structural obstacles. This was mainly due to the fact that I was out an hour early.

The render below details my observation taken from 20:20 UT to 20:38 UT. The moons from left to right are Ganymede, Callisto, Europa and Io.

As the moon was to rise much later, I took the opportunity to resume the DSO hunt by returning to my search for M51. I began by sweeping the sky eastwards around Perseus and Andromeda with my Bresser 10×50s’ to give my eye’s a chance to adapt to the dark. M31 was well placed as was the double cluster (NGC 884 and NGC 869) in Perseus. While there was not a cloud in the sky, the transparency was not that brilliant.

After about twenty minutes I couldn’t resist a look at M31 through the 25×100s’, and what a view. Amazingly, some of the dark subtle veins of the spiral structure were just visible while the small faint companion M110 was positioned about 10 arcminutes above.

From here I began a refreshed search for M51. I searched for over an hour and think I may have found the elusive spiral galaxy, but the view was so faint that I couldn’t be sure. The final diagnosis . . . I need more light gathering power to fully see M51. This is one DSO that I think I’m going to have to let go for the moment.

I ended my session at 22:30 UT with a view of the Pleiades rising in the east. The orange haze of the light pollution and the bad sky transparency made the open cluster appear quite faint to the naked eye, but through my 10×50s’ was easily recognizable. Not the best view due to the LP, but still a rewarding sight.

Jupiter and the Moon

For the first time in about two weeks I finally managed an observation of Jupiter as it meandered into the south west. This really was an awkward observation though. What makes things difficult is that my view from the south east to the south west is blocked by several tall buildings, so for around ten minutes Jupiter disappeared from view behind one of them. I moved my position more than once to try and get a better view. Finally Jupiter reappeared and I managed around ten minutes of viewing before the clouds blanketed the western sky.

I made the following render in Photoshop of my observation. The moons from left to right are Ganymede, Io and Europa. For some bizarre reason I never observed Callisto, which should have been within another 10 arc minutes or so to the left of Ganymede. Trying to find an optimum viewing position possibly distracted me - either way, it was nice to see the giant king of the solar system again.

The waning gibbous moon was also on show later on that evening, rising gracefully out of the eastern horizon. This really is the best time to observe and photograph the moon with it’s black terminator, debossed shadowy craters and sublime surface detail.

I captured two Afocal images through the Pentax Optio last night. The first one required a little smart sharpening in Photoshop, but even without this  the level and clarity of detail is excellent. The second one is also a good shot, but it lacks the clean focus of the first capture and required a harder level of sharpening. These two images for me, are the best Afocal photographs I have taken to date. Just shows what you can achieve with a simple digital camera.

A Perpetual State of Low Pressure

At about 11:00pm last night (17.09.08) the cloud cover finally abated at last and a large patch of clear sky was visible, albeit for half an hour. This gave me just enough time to get the tripod, my 25×100 bins and my Pentax Optio S50 digital camera set-up for a short photography session.

The seeing was quite good but the sky transparency as usual left a lot to be desired. From the crop of Afocal shots that I managed, the one above is by far the best. With the addition of some post processing in Photoshop, I managed to enhance the image so that surface detail is far more visible.

As can be seen, the Mare Crisium has almost vanished from view while the ray craters’ Tycho, Copernicus, Kepler and Aristarchus are less pronounced but still observable. Visible to the east of Tycho are the prominent craters Maurolycus and Barocius while further east still can be seen Janssen, Fabricius and Metius. Traveling in the opposite direction to the western limb of the moon, the basin crater Grimaldi can easily be seen just below the vast expanse that is the Oceanus Procellarum.

While this image has a degree of depth to it, it’s not the best I have taken thus far. Imaging will definitely be at it’s most interesting as the moon enters it’s last quarter and crescent phase. As ever though, my observing sessions are becoming less and less as the British weather seems locked in a perpetual state of low pressure. Decent observing conditions are become a rare thing so hopefully there will be some good clear nights coming my way very shortly . . .