Go Back   IceInSpace > General Astronomy > Observational and Visual Astronomy
Register FAQ Calendar Today's Posts Search

Reply
 
Thread Tools Rate Thread
  #1  
Old 07-10-2012, 03:02 PM
Paddy's Avatar
Paddy (Patrick)
Canis Minor

Paddy is offline
 
Join Date: Jun 2007
Location: Strangways, Vic
Posts: 2,214
Small Magellanic Cloud tour #1 - the northeast.

Due to the ongoing nature of my obsession with the Magellanic Clouds and encouraging other folk with scopes to become similarly obsessed, I present my latest project - cluster hopping tours of the Clouds.

This is no.1, the northeast section of the SMC. I'd appreciate any feedback about the clarity and usefulness of the "tour" instructions. I will be loading the tours onto the site as well.

Charts can be downloaded at

cloudsofmagellan.net.au

SMC Tour #1 – Northeast
As the SMC changes it’s orientation as it circles the South Celestial Pole (SCP), I will us the terms preceding (p) and following (f) instead of West and East respectively. Preceding is the side of the field of view that objects move towards, following is the side they move from. I use the term North to mean away from the pole and South to mean towards the pole.
It will also help if you know the field of view of your eyepieces. This will help you find the angular distance between the object in minutes. If you’re not familiar with how to calculate this, it is the apparent field of view of your eyepiece (eg 80 degrees for a Nagler) divided by the magnification in your scope and multiplied by 60 to give the result in minutes. The magnification is the focal length of your scope divided by the focal length of the eyepiece.
This first “tour” covers objects in the north east (Nf) area of the SMC. A magnified finderscope will be very helpful in getting started, but otherwise a wide-field eyepiece should suffice. These notes have been made using a 16” F4.9 telescope under dark skies. Some of the fainter objects may not be visible using smaller scopes or with light-polluted skies. A 10-12” scope under good conditions should be enough to see just about all of these objects and an 8” will see most.
SMC charts 1 & 2 from cloudsofmagellan.net.au cover the objects in this tour.
These descriptions don’t include observations with a nebula/UHC filter. As many objects include emission nebulae, they are well worth viewing with filters as well as without.

Getting started. If you look at the SMC with a magnified finder or binoculars, you will see that the brighter parts of the galaxy look a bit like a comma, with the tail to the east (following) and the round smudge of 47Tuc to the north of the head of the comma. Looking at the tail with a finderscope, you will see 2 bright knots. Centre the scope on the innermost (preceding) knot. This is our starting and reference point, NGC 346. If you’re using a low power eyepiece, you will find a p-f string of objects in the tail of the SMC, most likely the smallest bright one at the p end is NGC 330. Centre your scope on the one to the f side and you are at NGC 346.

NGC 346 is a complex open cluster and emission nebula, reminiscent to me of a barred spiral galaxy in appearance. There is a 5’x2’ N-S central bright core embedded in a circular disc which is itself embedded in a 6’ N-S x 10’ p-f fainter haze, which is Henize emission nebula N66. NGC 346 is the largest and most active star-forming region in the SMC, as NGC 2070, the Tarantula nebula, is the most active star forming region of the LMC.

25’ f of NGC 346 is NGC 371, another large open cluster and emission nebula, not quite as bright as NGC 346, but still very obvious in a magnified finder as the bright knot just following NGC 346. It looks to me about 7’x12’ and is littered with resolvable stars.

10’ f of NGC 371 is the smaller and fainter, but again still quite bright, is NGC 395 another open cluster and emission nebula which looks about 3-4’ across. More challenging for smaller scopes is emission nebula IC 1624, a small but distinct glow 3’ S of NGC 395 and following a bright foreground star.

Come back to NGC 371, the second bright nebula that we visited. 7’ to the south of it is a N-S line of 3 stars. Just preceding this line of stars is the small glow of open cluster Kron 50, which forms the apex of a triangle with the row of 3 stars as the base.

Now return to NGC 346, our starting/reference point. You might want to have chart 2 ready. 30’ to the S-p of NGC 346 is the lovely, very bright small open cluster NGC 330. This is one of the SMC’s gems – a 2’x1’ lens shape of myriad tightly packed and still resolvable stars. Draw a line from NGC 330 back to NGC 346 and about halfway along and 2’ to the north of the line is the faint, small glow of open cluster Lindsay 56.

Come back to NGC 346 again. 14’ to the S is a flattened triangle of three small round glows, the apex of the triangle to the p side. The brightest of the 3 and closest to NGC 346 is IC1611, the next brightest (the apex) is IC1612 and the one furthest from NGC 346 is Kron 42. All of these are open clusters.

Get chart 1 out again.

From NGC 346, return to NGC 371. Imagine a line drawn from the centre of NGC 371 through the fainter, following NGC 395 and extend it for 25’ where you will find a bright foreground star. 10’ to the north of this star is the very round small glow of open cluster NGC 411. 10’ following the aforementioned bright star and forming a triangle with the star and NGC 411 is the very faint NGC open cluster NGC 412. This may well be beyond small scopes and poor skies. Also on the faint side is the larger 4’ open cluster Lindsay 84 which forms the S apex of a triangle with NGCs 395 and 411 as the base. Lindsay 84 is a soft glow with a brighter centre and several resolved stars.

Come back to NGC 411. 20’ Np is a bright foreground star. A further 25’ Np is the 3’ dia. circle of open cluster NGC 361, just before another bright foreground star.
Reply With Quote
  #2  
Old 07-10-2012, 06:47 PM
Zubenel's Avatar
Zubenel (Wes)
Awe and Wonder

Zubenel is offline
 
Join Date: Aug 2005
Location: SE QLD
Posts: 594
Wow , What an awesome resource you have provided. I must admit that even those who have have been doing astronomy for more than a few years still get "lost" in here . Thanks
Reply With Quote
  #3  
Old 07-10-2012, 06:57 PM
bartman's Avatar
bartman (Bart)
1 of 7 of 9

bartman is offline
 
Join Date: Sep 2009
Location: Perth
Posts: 1,968
Thanks Patrick!
Ill have to print this out and follow!
Cheers
Bartman
Reply With Quote
  #4  
Old 07-10-2012, 11:39 PM
pgc hunter's Avatar
pgc hunter
Registered User

pgc hunter is offline
 
Join Date: Feb 2009
Location: Renmark, SA
Posts: 2,993
Great site indeed Patrick. Although might I suggest changing the red font on the home page, somehow that red on blue just has me trippin balls

The photographic charts are really good and I like the inclusion of sketches through various scopes. Really gives a first hand account of how visually rich these galaxies are through a telescope.

What I'd love is a 26mm Nagler, 2" UHC and my 12" in a dark site and just cruising through the LMC.
Reply With Quote
  #5  
Old 08-10-2012, 11:11 AM
mental4astro's Avatar
mental4astro (Alexander)
kids+wife+scopes=happyman

mental4astro is offline
 
Join Date: Jun 2008
Location: sydney, australia
Posts: 4,995
I've been a fan of your Magellanic project for some time now.

I particularly like that you've also got "binocular charts" that highlight the brighter objects within both galaxies. I'm using these to chase down/identify objects to sketch.

This tour that you've prepared is an excellent project. A great resource for when anyone wants to spend time just on these galaxies.

Mental.
Reply With Quote
  #6  
Old 08-10-2012, 04:42 PM
Paddy's Avatar
Paddy (Patrick)
Canis Minor

Paddy is offline
 
Join Date: Jun 2007
Location: Strangways, Vic
Posts: 2,214
Thanks all - your replies are very encouraging! Sab, I have struggled with that font on the home page endlessly. Alas the wywiwyg software that I use has a glitch and keeps putting it back that way and as it is an unusual program it uses lots of JAVA and won't be edited by other programs. As I've done all the charts with it I can't redo the site with a new program without spending 100s of hours on it. They have just brought out a new version, so hopefully an upgrade will do the trick.

Lesson, don't buy cheap web editing software!
Reply With Quote
  #7  
Old 11-10-2012, 12:43 AM
andyc's Avatar
andyc (Andy)
Registered User

andyc is offline
 
Join Date: Dec 2011
Location: Sydney
Posts: 1,008
Love your charts Paddy - have a printed copy of the annotated charts so I can explore the Clouds whnever I can, they're getting more use now it's the "cloudy" time of year! Definitely the best resource available for exploring the Clouds - as a northern hemisphere astronomer, they were the thing I most looked forward to seeing on coming south as there's simply nothing like them in the north. Galaxies where you can see the larger-scale structure, yet pick out individual stars, nebulae and massive clusters, very cool indeed.

I'll definitely have a go at your tour at the next opportunity, and look forward to a few more.
Reply With Quote
  #8  
Old 14-10-2012, 09:45 PM
Rob_K
Registered User

Rob_K is offline
 
Join Date: Oct 2006
Location: Bright, Vic, Australia
Posts: 2,183
Hi Patrick, couldn't resist after all the great work you've put into this!

So I did the 'tour' in pretty good skies tonight, 4.5" f8 reflector and 21mm eyepiece (43x). NGC 346 is a bright patch of nebulosity but I couldn't pick up the fainter extensions. NGC 371 showed as a reasonably bright nebulous patch and I was quite taken with the view, more subtle than 346. NGC 395 was just visible but the nebulosity was quite clear in averted vision. Lindsay 84 was harder again, difficult in direct vision but easier in averted vision. NGC 330 was easy, a bright small object at the low mag I was using, round with a brighter centre.

Then it got tougher! I could see NGC 411 in averted vision as a tiny dim patch but I didn't really get a glimpse of nearby NGC 422. NGC 361 was visible in averted vision, maybe a little more difficult than 411. IC 1624 was just visible, but of the triangle of tiny clusters near NGC 346, I could only clearly see IC 1611 (averted vision). Lindsay 56 was a fairly easy get but tiny and almost star-like. Didn't see a sign of Kron 50.

On another note, I tried for comet C/2011 L4 (PANSTARRS) tonight to see if it was in visual range of a small scope, and lo-and-behold I did manage to see it! But barely. It's a bad position for me, low in the west after sunset and in the skyglow from town. I could see it fairly well but only while moving the field or tapping the eyepiece. As soon as I stopped any movement I couldn't really pick anything out. Should be a reasonable easy get in a bigger scope, but it is fast disappearing from our southern skies.

Thanks again Patrick, more power to you!

Cheers -
Reply With Quote
  #9  
Old 19-10-2012, 12:58 AM
Rob_K
Registered User

Rob_K is offline
 
Join Date: Oct 2006
Location: Bright, Vic, Australia
Posts: 2,183
Amazing the difference a better night makes, or maybe it's the fact I wasn't working backwards-&-forwards from chart to eyepiece tonight. 4.5" f8 reflector again at 43x (21mm eyepiece).

But there was much more to see anyway, what a beautiful field or two at low powers! I could pick up fainter extensions of NGC 346, and Lindsay 84 was quite easy (although dim) in direct vision. Could make out more of the tiny faint ones including NGC 422 in averted vision.

Away from the SMC, galaxy NGC 253 was stunning and I could see mottling and just make out some of the brighter 'lanes'. Maybe best view ever in this little scope, but then again my memory is not that... er... um... whatever... Comet 168P/Hergenrother was easy to see - I could make out about 4' of tail in around PA135 to 140. Had a squizz at ghost-galaxy NGC 247 and also the Fornax galaxy cluster. Tarantula Nebula surprisingly didn't look all that flash but 47 Tucanae was to die for!!

Cheers -
Reply With Quote
  #10  
Old 19-10-2012, 11:14 AM
ausastronomer (John Bambury)
Registered User

ausastronomer is offline
 
Join Date: Mar 2005
Location: Shoalhaven Heads, NSW
Posts: 2,620
Hi Paddy,

I really like the way you are putting this website together. I will be following its progress closely. It is going to be a tremendous resource for observers wishing to "get lost in the clouds".

As you know the information and charts available on the LMC and the SMC can sometimes appear a little light on and I sometimes get requests on how to find certain targets in the LMC and SMC, particularly Kron 7, which is one of the targets in my BAM600 - 600 target Southern Skies catalogue.

As you probably know my observing colleague Andrew Murrell had a website dedicated to the SMC for many years, but it has gone by the wayside. Andrew does still have all that material but at the moment it is sitting idle, which is sad. Andrews website used Mati Morels charts. With the advancements in technology your website looks really great.

Really love what your doing here Paddy, Keep it up.

Cheers,
John B
Reply With Quote
  #11  
Old 19-10-2012, 10:37 PM
Paddy's Avatar
Paddy (Patrick)
Canis Minor

Paddy is offline
 
Join Date: Jun 2007
Location: Strangways, Vic
Posts: 2,214
Quote:
Originally Posted by Rob_K View Post
Amazing the difference a better night makes, or maybe it's the fact I wasn't working backwards-&-forwards from chart to eyepiece tonight. 4.5" f8 reflector again at 43x (21mm eyepiece).

But there was much more to see anyway, what a beautiful field or two at low powers! I could pick up fainter extensions of NGC 346, and Lindsay 84 was quite easy (although dim) in direct vision. Could make out more of the tiny faint ones including NGC 422 in averted vision.

Away from the SMC, galaxy NGC 253 was stunning and I could see mottling and just make out some of the brighter 'lanes'. Maybe best view ever in this little scope, but then again my memory is not that... er... um... whatever... Comet 168P/Hergenrother was easy to see - I could make out about 4' of tail in around PA135 to 140. Had a squizz at ghost-galaxy NGC 247 and also the Fornax galaxy cluster. Tarantula Nebula surprisingly didn't look all that flash but 47 Tucanae was to die for!!

Cheers -
Thanks John, I really appreciate your response!

Quote:
Originally Posted by Rob_K View Post
Hi Patrick, couldn't resist after all the great work you've put into this!

So I did the 'tour' in pretty good skies tonight, 4.5" f8 reflector and 21mm eyepiece (43x). NGC 346 is a bright patch of nebulosity but I couldn't pick up the fainter extensions. NGC 371 showed as a reasonably bright nebulous patch and I was quite taken with the view, more subtle than 346. NGC 395 was just visible but the nebulosity was quite clear in averted vision. Lindsay 84 was harder again, difficult in direct vision but easier in averted vision. NGC 330 was easy, a bright small object at the low mag I was using, round with a brighter centre.

Then it got tougher! I could see NGC 411 in averted vision as a tiny dim patch but I didn't really get a glimpse of nearby NGC 422. NGC 361 was visible in averted vision, maybe a little more difficult than 411. IC 1624 was just visible, but of the triangle of tiny clusters near NGC 346, I could only clearly see IC 1611 (averted vision). Lindsay 56 was a fairly easy get but tiny and almost star-like. Didn't see a sign of Kron 50.

On another note, I tried for comet C/2011 L4 (PANSTARRS) tonight to see if it was in visual range of a small scope, and lo-and-behold I did manage to see it! But barely. It's a bad position for me, low in the west after sunset and in the skyglow from town. I could see it fairly well but only while moving the field or tapping the eyepiece. As soon as I stopped any movement I couldn't really pick anything out. Should be a reasonable easy get in a bigger scope, but it is fast disappearing from our southern skies.

Thanks again Patrick, more power to you!

Cheers -
Great to have such a good night and well done on seeing such detail with the trusty Tasco and those eagle eyes!
Reply With Quote
  #12  
Old 20-10-2012, 01:39 PM
Rob_K
Registered User

Rob_K is offline
 
Join Date: Oct 2006
Location: Bright, Vic, Australia
Posts: 2,183
Interesting, there's an AAVSO Alert Notice out for an eclipsing binary star in or over NGC 346, HD 5980.

"HD 5980 is an eclipsing binary in the Small Magellanic Cloud. The system consists of two massive, stars that both have a strong wind. The primary star is a luminous blue variable (LBV) and is unstable, having erupted in the 1990s to become the visually brightest star in the SMC. The secondary star is a nitrogen-enriched Wolf-Rayet star (WN). The orbit is slightly eccentric with a short 19.3 d period. As the stars orbit each other, their strong winds collide, bringing about changes in multiple spectral lines, small changes in the brightness of the system, and strong X-ray modulation."
http://www.aavso.org/aavso-alert-notice-472

Currently reported at mag 11.6V, primary eclipses are predicted at the following times:

JD 2456220.8 (2012 Oct 20)
JD 2456240.0 (2012 Nov 8)
JD 2456259.3 (2012 Nov 27)
JD 2456278.5 (2012 Dec 17)
JD 2456297.8 (2013 Jan 5)
JD 2456317.0 (2013 Jan 24)

Co-ordinates are RA = 00 59 26.57, Dec = -72 09 53.9 (J2000.0).

Would be cool to follow it for a while.

Edit: Just checked the ASAS-3 light curve, the eclipse isn't a spectacular one, around half a magnitude or so, but still should be detectable visually -
http://www.astrouw.edu.pl/cgi-asas/a...1.2290,500,0,0

Cheers -

Last edited by Rob_K; 20-10-2012 at 02:27 PM. Reason: Light curve link added.
Reply With Quote
  #13  
Old 29-10-2012, 08:56 PM
Gem's Avatar
Gem (Grant)
The serenity...

Gem is offline
 
Join Date: Mar 2011
Location: Canberra, Australia
Posts: 926
Good work! Thanks!
Reply With Quote
  #14  
Old 01-11-2012, 08:04 AM
Paddy's Avatar
Paddy (Patrick)
Canis Minor

Paddy is offline
 
Join Date: Jun 2007
Location: Strangways, Vic
Posts: 2,214
Thanks Grant!
Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 12:32 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement