The last few months has seen an amazing amount of activity in this forum. Sketching has had a particular resurgence, covering subjects from the Moon, to the Sun, planets, and beyond.
Please note, never, ever look at the Sun directly through a telescope- it will blind you instantly. Sketches submitted in this forum have all been done utilising specialised solar filters.
This month will try to build upon this activity, with the added bonus of a comet too.
You may like to have a go at sketching any one or more of these. It's not a competition, but an exercise in increasing our observation skills. Stuck on where to start or how to go about it- just ask.
Comet Hartley- This comet is currently close to magnitude 5 in brightness, making it just visible to the naked eye from a dark site. It is located just north of the constellation Orion. Glenc has posted a couple of good maps to help find it this month:
"The Killing Fields"- Refered to in last month's Challenge, this time the focus is on this marvelous group of objects, some of which are visible to the naked eye. So named as the objects in focus are either being consumed or are the remains of being destroyed by our Milky Way galaxy.
This section of the sky in the constellations Dorado, Mensa & Tucana, contains the irregular galaxies the Large Magellanic and Small Magellanic Clouds (LMC & SMC respectively), and the giant globular cluster 47 Tucana (also known as NGC 104).
The LMC & SMC are in the process of being consumed by our own giant
galaxy, the Milky Way. These two galaxies are also gravitaionally interacting, with long exposure photos showing tendrils of gas and stars being flung off each due to the gravitational tidal effects. These two galaxies in their own right contain all the elements found in their more famous spiral cousins- globular clusters orbiting them, open cluster, bright nebulae and stars in every stage of stellar development, all of which are observable. Of these, the Tarantula Nebula is the most remarkable. This giant cloud of gas and dust is the most massive stellar nursery known anywhere, dwarfing the Orion Nebula. Within this cloud are also some of the most massive stars known, which are also observable in modest scopes as the brightest shines at magnitude 9.
Paddy has being undertaking an incredible task of observing and recording his observations of the hundreds of objects just within these two satellite galaxies of our Milky Way
47 Tuc is not a 'normal' globular cluster. For one it is just so damn big, and the range of stellar population indicate that it is the remnant core of a long devoured galaxy now in or
bit within our Milky Way. The only larger globular cluster, Omega Centuri, is also a remnant core. Normal globulars typically contain the same type of star, both in composition and age with no 'recent' stellar formation. 47 Tuc and Omega Centuri contain a wide variety of star generations and sizes which can only suggest they are of extra galactic origin.
If you up for another challenge, within the huge circular boundary of 47 Tuc lie three other 'normal' globular clusters. These are not associated with 47 Tuc, but happen to lie within the line of sight, and may be associated with the SMC. Astroron has posted a good referrence picture to help track down is quartet:
M77, in Cetus, is a relatively bright face-on sprial galaxy. It is one of the brightest barred galaxies, with its bar being visible in 10" scopes. It is also known as a Seyfert galaxy, which are known for having a very active core.
The first pic below is a NASA photo of M77. The second shows the LMC (on left) the SMC (right) and 47 Tuc (the large bright 'star' to the right of the SMC).
Any further suggestions?
Enjoy & clear skies,
Mental.
Last edited by mental4astro; 29-10-2010 at 12:23 AM.
Reason: A bit more info
The following 24 Dunlop objects are visible in Spring.
Dunlop saw, and in most cases found, these with a 9" reflector in 1826 from his backyard in Parramatta.
His 9" was equivalent to a modern 6.5" Newtonian.
The brightest and best objects in the southern sky were found by Lacaille, James Dunlop and John Herschel.
This month is turning into one with an inter galactic flavour. Sweet (I like my food analogies).
How about we also give the Moon a gernsey too. The old dear gets a bit of a bad wrap when she does her best to light up the dark night, so sad. However, the last Moon has also seen several sketchs of her posted.
Paddy & Michael have also started a theme of 'sketch the Moon night', where a particular feature is designated as the sketch target on a particular couple of nights. Tonight (?) I believe is the last of those two for the very first "Sketch the Moon Night" as further phase changes the target too much for comparison of sketchs posted:
Great idea to focus on the Magellanic Clouds, Alex.
With a computer literate friend in Melbourne, I am in the process of developing a web site devoted to the Magellanic Clouds. The idea is to have charts to help people find their way through the abundance of DSO these galaxies have to offer, images related to the objects, sketches, observing reports and links to scientific articles related to the Clouds and their DSOs.
I am at present doing the charts for the SMC using modified Sloane DSS images downloaded through Wikisky (the LMC is going to take quite some time). I convert the images to greyscale and simplify them by adjusting contrast and brightness. Iam labelling them having identified objects using Mati Morel's excellent "Visual Atlas of the Small Magellanic Cloud", Wikisky and Brent Archinal and Steven Hynes' "Star Clusters".
I am posting 3 charts and an interim Key chart (the one on the web site will be much better and use an image from a talented IIS imager instead of the ordinary DSS offering used here) and I will add a few more over the coming days as I get them done. I would be very grateful if a few folk could print them off and see how they go finding objects with them. Any suggestions for improving them would be most appreciated. The images on the site will be a bit different as I anticipate that the labels will also be links to information, notes, articles and images. I am setting them up to be printed on A4 pages.
NGC items just have the number. L stands for Lindsay, K for Kron and N for Henize Nebula catalogue. I suspect that scopes less than 10" or in light polluted areas may not show some of these. I'd be very interested to hear what people can find with different observing conditions.
North is up as this is the way it will be when the clouds are highest in the sky. I hope to have inverted viewing friendly version on the site. Eventually. Each chart is about 75' north to south.
As I said, I'd very much appreciate people playing with these and letting me know how you go.
The charts are in the order Key, 1,2 & 3. More to follow soon.
I would like to encourage people to look at the Dunlop objects.
After the Herschels he found more bright deep sky objects (DSO) than anyone else.
He found 5.5 times more objects than Messier.
I just counted all the NGC objects found before the year 1839.
Eight people found most of them.
1. William Herschel found 2,444 NGC objects including 2,109 galaxies
2. John Herschel (William's son) found 1,738 NGC objects including 1,150 galaxies
3. James Dunlop found 228 southern NGC objects from Sydney
4. Charles Messier found 41 NGC objects from Paris
5. Mechain found 27 NGC objects from Paris
6. Lacaille found 23 southern NGC objects from Cape Town
7. Hodierna found 11 NGC objects from Sicily
8. Caroline Herschel (William's sister) found 10 NGC objects
"Thus, at the end of 2000, the ICQ adopted the practice of eliminating the suffixed numerals to comet names; this does mean, however, that permanent numbers or year/letter/number designations must be used with the name (of course, it is sufficient to use the permanent numbers or designations alone without the name, but not vice versa). The IAU adopted a policy of *optionally* including or excluding suffixed numerals to comet names when it approved the new set of comet-naming guidelines in March 2003. Thus, the Minor Planet Center and the Central Bureau for Astronomical Telegrams also no longer use comet-name suffixed numerals. (While a few people who have dealt a lot with comets over the last several decades will wish to continue using the redundant suffixed numerals for nostalgic reasons, such use will fade into oblivion during the next generation of astronomers -- so one might as well stop using them now and concentrate instead on the more logical prefixed numerals. This will make it easier on astronomers of the future, who will soon be wondering what the suffixed numerals stood for in the "old" literature, as the old suffixed numerals fall rapidly into dis-use.)" http://www.icq.eps.harvard.edu/cometnames.html
"I've also come across this listing called the "Dunlop 100". You, Glen?"
Yes Alexander that was me. That came from James Dunlop: Messier of the Southern Sky. Sky & Telescope June 2001, p. 112-116
Saturday night's sojourn to a dark site was saddly fruitless. The cloud cover that had been expected to clear over the early evening didn't, . Still, the five of us photon junkies that made the 200km round trip just for pizza still had a good time!
I did manage a two hour session last night from home with my mate 'hickny' & 'craigS'. Exhaustion and high cloud rolling in killed the session, so no sketching done. Still, we managed to pin a few targets of the November Challenge.
47Tuc is always a treat. Light pollution though didn't allow me to pin the three fainter GC's that lie within its boundaries.
The Tarantula was next. First without filters it is just a small smear. Then, with an OIII filter, WOW! The spider more resembled a grotesque satanic rams head, with dark hollowed eyes and huge wide arching horns and tendrils occupying the field of view. Another interesting thing was without the filter, the cluster of super giant blue stars at the centre of the spider are clearly visible. With the filter, they just about disappear. Cool! There are some inexpensive nebula filters made by GSO, and are worthwhile considering for visual use. The OIII filter I use is one of theirs. Makes all the difference to me under Sydney skies.
I then had a 'why the heck not' go for the barred galaxy NGC 1365. Took a bit of getting, but to my surprise I spied out an oval smudge. It was a brief encounter as high cloud soon consumed it. I was encouraged, though, as it means it is certainly obtainable from Sydney still, and a sketch candidate from home.
Though not part of this month's Challenge, Jupiter had a nice surprise for us, with a shadow transit being visible. Its trek across the disc was noticed over the two hour session we had! Nice treat.
This leaves the Moon as my last November target. The thread "Sketch the Moon Night" has the current target features if you fancy a go with a pencil an paper. Michael has also posted a great link on 'how to' sketch the Moon in the 'Sketching Tips' thread.
,
. Still, the five of us photon junkies that made the 200km round trip just for pizza still had a good time!
