Observing Report 19th April 2010

[Moonshane]

Observing Report 19th April 2010

Location Stockport

Equipment - 12" f5.3 Orion Optics UK Dobsonian

I decided to try and work my way through the double stars that I have never seen in Boötes and then move onto other deeper objects etc. Here's a brief summary of the objects I managed to pick up. Transparency was very good and seeing reasonably good (see below) but there was a little moonlight and the sky was actually brighter than it had been recently.

As usual, after cooling and collimating the scope, I lined up my finder scope and Telrad on Polaris. Even at low magnification this generally shows the smaller, dimmer companion star. For those that don't know, this star hardly moves during the night / year and is therefore a good star for setting up. I cannot stress enough how much a Telrad/right angled finder/ wide field eyepiece have helped my in locating targets with both the dob and my refractor.

All lined up, I then turned to an evergreen favourite, Saturn. This is a wonderful object through any scope and tonight proved to be no exception. I managed to see at least six moons (possibly seven). I really must check Stellarium before I look next time (possibly at the weekend) and see if I can put names to them. There were three tiny dots under the rings, and others much more widely spaced from the main planet. The Cassini Division was obvious at this magnification (approx 220x with the 2.5x Powermate and 18mm Radian). The planet constantly popped in and out of sharpness as the atmosphere bubbled. Mars was such a small dot compared with earlier in the year I did not bother with the scope. Venus had been seen earlier in the evening by naked eye but my house faces east and I cannot get a view of this through the scope from my garden. The moon was just beginning to show a nice crescent but had also moved too far around by the time I was observing.

Moving over to the constellation of Boötes, I set about trying to find the various doubles which I had not previously seen. I had already had a decent look at Epsilon Boötis (Izar) so I left this one out. I have also seen Mu Boötis (Alkalurops) before with my refractor and although it split the secondary cleanly into its two components, I wondered if the split would be more obvious in the dob. In the end the views were actually quite similar but I'd say the dob just edged it. The primary was much brighter than the secondary/tertiary combination.

The next target was Kappa Boötis which is quite a widely spaced double up near to Ursa Major. I could only pick out hints of the blue/yellow colours mentioned in my sky maps (I am finding <The Constellations> VERY useful for setting targets for a night's viewing, usually in conjunction with Turn Left at Orion). I then moved on before I noticed that the map notes said that another double Iota Boötis could be seen in the same field!! Back then to Kappa Boötis and yes, there they were. Iota being a much wider split than Kappa and the combined image very lovely indeed.

I then moved over to the lower side of the constellation and in truth found the markers a little tricky to see given my sky is reasonably light polluted. My neighbour's eyes must be better than mine as he could see them far more clearly. We tried Zeta Boötis but the secondary is less than one arc minute away from the primary and I could only see a hint of something to one side of the main star and therefore could not see the split on this one. Xi Boötis was the next target and really is a lovely sight. If you have never seen a pink star then look for this one; it makes for a lovely contrast with its yellow companion. The star is readily split and was my favourite double of the night. Our final target was Pi Boötis which according to my map notes has two blue white stars. To my eyes they were more yellow in tone than blue but perhaps this was a bias in my eyepieces. I think that Televue sometimes seem more yellow than others? I'll check this next time with the refractor.

Finished with Boötes, I then wanted to see more of some of the DSOs I have seen previously and ended up with one surprise. I really don't mind seeing targets again for a second or subsequent time as 1) it's always good to practice finding objects, 2) you seem to notice something different each time with varying quality of seeing etc 3) the lose nothing at all with further views!

The first target was M13, The Great Hercules Cluster. I had seen this briefly through the refractor previously and although I was resolving stars, this was nothing compared with that in the dob. In the larger scope it was a lovely object with hundreds of stars visible especially with averted vision. It got better as it got higher in the sky too so it's worth revisiting later in the night/year if you get the chance.

By way of comparison I then moved over to M3 and this was in comparison with M13 a much more compact ball of stars and again a really spectacular sight. I feel that M13 just edges the beauty stakes for me though.

My mate had never seen M65 and M66 over in Leo and we turned the dob to these. The view was in no way comparable to the last view I had of these with the same equipment, as the sky was much lighter and the galaxies therefore much fainter. They were still noticeable though with direct vision but better with averted vision.

M53 is a smaller but bright globular cluster in Coma Berenices and again was so much better in the dob than with the refractor with which I had seen this previously. We also saw the nearby galaxy M64 (the Blackeye Galaxy) which was again affected by the light sky.

As a test I then moved up to Ursa Major to have a look at M81 and M82 as these have always been very bright and obvious in the past. They were still comparatively bright but much more faint than previously and on this basis I knew it was not really a night for galaxies. I wonder if volcanic ash in the atmosphere could be affecting the seeing.

Given the above comments, M51 was not likely to be seen well and I struggled with this and failed to locate it at all.

After another look at M13, I moved across the 'Keystone' in Hercules and took a look at it's fellow globular, M92. This was again seen in more detail than last time with the refractor. It appears that aperture is very important for globulars, even the brighter ones.

The constellation of Lyra is just starting to get viewable around midnight for me now in the north east and I took a look at Vega through the scope. This really is an amazing star to look at through a scope. So steady and bright - lovely. Just below this was M57 the Ring Nebula. Like a tiny smoke ring in the sky, it took magnification quite well - always a favourite of mine. Further down again and you can just see Beta Cygni (Albireo) which is a really easy split but being a little low currently, the colours don't really shine yet. Epsilon Lyra (the Double Double) was also split cleanly with various magnifications up to 320x.

The surprise I mentioned was that my mate asked, almost as he was leaving, if I knew about the Coma Star Cluster. The what? I said, and he quickly picked up this excellent cluster in Coma Berenices using the binoculars. The whole field was filled with lovely blue stars and what a brilliant site and way to end the night. Never seen this before myself but will be looking for it again. Like M44, the Beehive, this can be seen with the naked eye so worth looking at. Here's a link with more details <Coma Berenice star cluster>

As always, I've waffled on a bit but hopefully other newly 'baptised' astronomers will find this useful as a guide to what they can possibly find from their own gardens with their own scopes.

[mdstuart]

You have just listed everything in this months Astronomy now!

[Moonshane]

ha ha

pure coincidence I assure you! I don't subscribe - maybe I should?

This was a really nice night again - it's amazing what you can squeeze into a few hours even when not very experienced like what I am (BTW the last comment is in honour of Ernie Wise and the best plays what he ever wrote..... a true non-eclipsing binary (Eric and Ernie) if there ever was one - where the hell did that come from??.)

I am really lucky that the darkest sky is East of me and that it the way my garden faces. I can see to the north, east and south - bad LP in the south and out of site in the northwest but about as good as it can get really from my location.

[Doc]

A very thorough and detailed report, it made a very interesting read. Also a like the blue highlights

[Moonshane]

cheers Mick

you know darn well that I nicked the highlighted text idea off you

reckon it really works well and breaks up a long report.

had to go for light blue being a Manchester City fan!

[DarkerSky]

Super report Shane. I havnt spent much time in Bootes on doubles. Xi Bootis sounds like a cool combination. A pink star might even be enough to get my daughter interested

[Moonshane]

cheers Seb, glad you enjoyed it!

I thought just the same thing but my two are snared by the lure of facebook!

[albedo0.39]

Hi Shane- really nice to see yet another good observing report and thanks for putting so much effort into the write up.

How dark are your skies where you live ? I used to work in an around where you lived, and from memory recall the LP was none too clever...

[Moonshane]

hi Steve

cheers! I really enjoy writing my sessions up as they allow me to relive the enjoyment of a good session - I post them in the hope that other newbies can see what's about and 'findable' with almost no knowledge but a little planning.

I agree the LP is 'bobbins' where I am but I am lucky in a number of ways:

my garden faces due east approx which is towards the peak district.

the worst LP is NW and W of me which is the other side of my house

I can see N, E and S so get things as they rise

we built an extension to the house which basically covered the drive so as our gardens are back to back I am in a bit of a black hole with not much direct local LP to worry about (apart from kitchen windows etc.

I think this is why I can see so much and I am happy with the numbers of targets I am getting currently. I intend to get over to my brother in law's area - he lives in Glossop and tells me he sees the Milky Way naked eye regularly in one spot where he goes for a walk - never got to a darker site yet - this is an important point I reckon - you don't need to get to a pitchy black site in mid Wales to improve your view - just somewhere DARKER :0)