I'm making this Obs. Challenge for both December and January due to fore seeable complications of the festive season. I apologize if this annoys fellow IIS'ers.
Part I
Hail Australia's first great astronomer - James Dunlop
This Obs. Challenge has a distinct pioneer flavour. James Dunlop is regarded as Australia's first great astronomer, even regarded as one of the Southern Skies first great astronomers. His many hundereds of object discoveries all being catalogued from the now non-existant Parramatta Observatory in Sydney's west.
The extent of James Dunlop's work is honoured with the official Dunlop Catalogue of objects.
Fellow IIS member, glenc, has done extensive work on the life of James Dunlop. The first part of this Challenge is a selection by Glen of Dunlop's discoveries, all of which are observable in amateur sized scopes. His 9.5" scope was of the optical quality of a modern 6" scope.
Open Cluster
NGC 2243 - in Canis Major. A faint OC, that could prove a little difficult to make out from the surrounding mass of stars
Globular Clusters
NGC 1261 - in Horologium. A 10" scope begins to resolve this GC.
NGC 1851 - in Columba. One of the better objects in 'The Dove'
NGC 2298 - in Puppis. A small GC that is heavily obscured by galactic dust.
Galaxies
NGC 1316 & 1317 - in Fornax. A pair of interacting galaxies. NGC 1365-1380 - in Fornax. The Fornax Cluster of galaxies. A spectacular grouping of galaxies. I spied out this cluster of galaxies this last Saturday night for the first time. A casual observation with my 10" scope counted 14 galaxies in very close proximaty, with NGC 1365 being one of the brightest barred spirals (one of last month's targets) NGC 1792 & 1808 - in Columba. Two spiral galaxies that are close in the single field of view. NGC 1487 - in Eriandus. The faintest galaxy Dunlop found. An interesting 'starburst galaxy' with massive stellar formation happening.
Planetary Nebula
NGC 1535 - in Eriandus. One of the brighter examples of a planetary nebula.
Part II
This second part is a selection of targets that highlight certain gems of the summer sky. Most of these targets will also be easier to acquire than most of the Dunlop targets.
M 42 The Great Nebula, in Orion. One of the most photographed targets by amateur astronomers, this distinctly fan shaped nebula offers masses of detail for all sizes of scopes. The largest of amateur scopes begin to reveal distinc pink and green colouration.
Mira, The Wonderful, in Cetus. The first variable star to be identified. This red star varies in brightness from a magnitude 2 at its brightest, down to nearly magnitude 10 at its dimmest over an 11 month period. It is currently just on its maximum brightness. The mechanism which causes this pulsation is thought to be the stage of its evolution which sees the pull of gravity & an irregular burning of its hydrogen fuel push and pull on the star, varying its brightness.
M45 The Pleiades, in Taurus. Also known as The Seven Sisters, and as Subaru in Japan (noticed the car maker's logo is the same as this cluster? No coincidense). This is a young open cluster of massive blue stars. Its remanent gas and dust cocoon still faintly visible in larger scopes, where a nebula filter may help with its observation. The distance of this cluster from us sees the current light we observe having left this cluster when Christopher Columbus discovered the Americas more than 500 years ago.
B33, the Horsehead Nebula, in Orion. This is a feature of the faint emission nebula IC 434. This faint feature is also known as a 'dark pillar'. This is a really tough bugger to spot. Reputedly seen in scopes as small a 6", a 10" is more likely to just, just make it visible and only in very dark skies. A specialised Hydrogen-Beta filter, or a UHC filter at a pinch, will greatly help show this very faint shadow against a very faint glow of its associated nebula.
Again, any other suggestions?
It's been a pleasure to compile this series of monthly challenges this year. I hope they have been of assistance to your observing pleasure and apprieciation of the night sky.
Merry Christmas everyone,
Mental.
Last edited by mental4astro; 30-11-2010 at 09:51 AM.
If you are keen on exploring more of the objects James Dunlop discovered, glenc has a thread going on the man and his work, along with many charts and observation notes:
Jeeps, the Horsey is a notoriously difficult object to observe. Yes, a damn dark sky is mandatory, but knowing where to look and what to look for also helps, and the quality of your eyes and your observation experience adds to the mix of factors.
The following link to an IIS thread deals with this topic very well. It covers observation techniques & tips, plus a chart or two:
Just one other thing to keep in mind with the Horsey - you will be looking for a dark 'finger' superimposed upon a very, very, very faint nebula. Almost like looking for a shadow on top of another shadow. This is one of the most difficult objects to see with amateur sized scopes!
Observing Galaxies
Saddly those pretty pictures we see of beautiful, graceful spiral floating star islands are not what we see through the eyepiece. Galaxies are also known as "faint fuzzies" as that is how we best see them. The key to see them is very much dependent on your observation technique. A larger telescope helps, but if your obs. technique isn't up to it, you just won't see many of them.
When scanning the area in question that you've narrowed the field to, the trick is to keep your eye open to a soft little blob that when your eye goes back to and the damn thing 'disappears', you've found it!!!
Averted vision is the technique where you look to one side of the object in question to see it better. It works because the most light sensitive area of our eyes surrounds the central focus of our human eyes.
If you still struggle to spot the faint little bugger when the scope is perfectly still, give your scope a little flick to generate a vibration through it. Our eyes are made to 'see' movement, and their sensitivity is reduced if the field we are looking at is still for too long. Ever think about why a rabbit sitting in a field is invisible, but once it moves, even a small amount, it stands out so obviously! Same thing.
I've been aware of this last 'trick' of causing movement in the field of view to 'see' better for more than 20 years. But it was only explained to me in terms of our physiology earlier this year about how and why it works! Thanks Wavytone!
A great list of items Alex. And thanks for compiling the challenges throughout the year. They've been very rewarding and interesting. I think they've also introduced a lot of us not only to new objects but to new aspects of observing. Not a simple task to put these together and you've done a great job. Hope you'll keep going with it for 2011.
Alexander, and I also echo what Paddy said so well.
It has been constant clouds in Brissy for the last month so I haven't even be able to tackle any of last month's challenges. I've printed them up anyway for whenever the weather clears. If the weather is good for December, it may turn out to be a monster challenge! .
Alex Some very good targets to observe if only the weather would cooperate
I have three scopes sitting in my front room and none has seen any Galaxy light for what seems like an eternity
But maybe Santa will give us some fine weather for Christmas
Alexander, and I also echo what Paddy said so well.
It has been constant clouds in Brissy for the last month so I haven't even be able to tackle any of last month's challenges. I've printed them up anyway for whenever the weather clears. If the weather is good for December, it may turn out to be a monster challenge! .
Suzy, It would be interesting to see what you can observe some of those galaxies from your place but if anyone can see them it will be you.You will surely give them a big nudge
I look forward to your reports, when mother nature gives us some good weather to take up the challenge
NGC-2419 most distant glob known (mag 9.1) (in LynX) from around 2.30am low in the NthEst Dec1st
NGC-2683 Spr Glxy (mag 10.6) border of cancer from around 3.30am low in the NthEst Dec 1st
M67 (Red cluster) halfwar between Procyon & Regulus
Suzy, It would be interesting to see what you can observe some of those galaxies from your place but if anyone can see them it will be you.You will surely give them a big nudge
I look forward to your reports, when mother nature gives us some good weather to take up the challenge
Thank you Ron - very kind words and encouragement.
I've just looked up how many light years away the Fornax cluster of galaxies are, and its 50,000 L/Y. So if one light year equals 6 trillion miles, that's ... forget it, my calculator makes no sense.
Not sure if my skills are up to these yet, but I'll give them a go . May need lots of councilling during and after - could get nasty (hope the possums stay away) .
I'm ready for my next observing report when the weather plays good as I have just bought a professional looking voice recorder from Jaycar. That mobile phone of mine will blind me no more. I'm armed and ready .
I've just looked up how many light years away the Fornax cluster of galaxies are, and its 50,000 L/Y. So if one light year equals 6 trillion miles, that's ... forget it, my calculator makes no sense.
Not sure if my skills are up to these yet, but I'll give them a go . May need lots of councilling during and after - could get nasty (hope the possums stay away) .
That distance should be more like 60 million light years. That's about 5.7x10^20 km or 570 000 000 000 000 000 000 km!
NGC-2419 most distant glob known (mag 9.1) (in LynX) from around 2.30am low in the NthEst
NGC 2419 is a fascinating object and is certainly among the easiest of the remote outer-halo globs to observe visually, but at 84.2Kpc distance, it isn't the most remote of all.
Eridanus (90.2Kpc), Palomar 3 (92.7Kpc), Palomar 4 (109.2 Kpc) and Arp-Madore 1 (121.9Kpc) are all more distant from the Sun and more distant (in that same order) from the galactic centre (1 Kpc = 3,260 ly) thereby placing AM 1 at almost 400,000ly and NGC 2419 at about 275,000ly. Yet all are gravitationally bound to the Milky Way!
Have seen Pal 3 in 31cm, Pal 4 in 46cm (both are extremely difficult targets) but not the other two. To see the other two ... you're going to need a bigger telescope !
Interestingly, NGC 2419 is intrinsically (ie in absolute magnitude and therefore almost certainly mass) the 4th brightest Milky Way globular after Omega Centauri (NGC 5139), M54 and NGC 6388. An amateur observer situated in the Andromeda Galaxy (M31) would find NGC 2419 the easiest of the Milky Way GC's to observe!
Just catching up on some threads.
Thanks Alex for some interesting targets each month.
Lets not forget it was Orestis who kicked this off at the start of the year. I hope his absence recently means he has been studying hard.
Just catching up on some threads.
Thanks Alex for some interesting targets each month.
Lets not forget it was Orestis who kicked this off at the start of the year. I hope his absence recently means he has been studying hard.
With every Challenge I've been writing up, it is Orestis I first think of before any object selection happens!
Orestis, your absence of late has been sorely noticed. All the best with school, mate, .
With every Challenge I've been writing up, it is Orestis I first think of before any object selection happens!
Orestis, your absence of late has been sorely noticed. All the best with school, mate, .
Hi Guys I'm Back.
Wow its been so long,I've missed you guys, i have only been popping in for brief viewings.
I have been busy with end of year exams all last 2 weeks and i just had a trigonometry test today.And the times were I had a a bit of time to spare for astronomy it was cloudy.Its been cloudy for so long here, hope you guys have had better weather.
I Will just like Say a very Sincere Thanks to all of the Observing Forum for contributing to my enjoyment of astronomy.A Big Thanks to Alex for keeping the challenge going, this month's challenge is awesome and I can't wait for holidays to have a go..
I hope to catch up with all of you guys.
Cheers Orestis
PS-Merry Xmas everybody and a Happy new year
NGC 2243
NGC 1261
NGC 2298
NGC 1792 and 1808
NGC 1535
I have previously done
NGC 1316 and 1317 (Would suggest those with dobs go for these early in the evening or well after midnight, very near the "hole" when I tried for them again last night!)
NGC 1365
Malcolm
The other December obs I will try for clouds permitting!
Last night I looked at NGCs 1261, 1851, 2298, 1316, 1365, 1380, 1808, M42 and M45 with 20x80 binos.
NGC 1851 is very bright in 20x80s and NGCs 1261 and 1316 are bright in binos. NGCs 2298 and 1365 are faint, and NGCs 1380 and 1808 are very faint in 20x80s.
I used a 12" Dob to see NGCs 1317 and 1792. Mira is fading now, but still easy with the naked eye.
Alexander, and I also echo what Paddy said so well. 
.
if only the weather would cooperate
but if anyone can see them it will be you.You will surely give them a big nudge
50,000 L/Y. So if one light year equals 6 trillion miles, that's ... forget it, my calculator makes no sense. 
I'm armed and ready 
.
