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Cosmic Challenge: The Southern Pinwheel

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#1 PhilH


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Posted 01 November 2021 - 05:10 AM

Have you ever heard of NGC 300, the Southern Pinwheel Galaxy? Were it positioned high in our autumn sky in a prominent constellation, you certainly would have. In fact, NGC 300, an Sc spiral tilted nearly face-on to our view, would be one of the season's showpieces, especially through large backyard telescopes. Because it lies in the far southern sky, nestled among the faint stars of Sculptor, it remains the purview of diehard deep-sky fanatics only.

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#2 Eclipsed


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Posted 02 November 2021 - 10:08 AM

I hadn't heard much about this Galaxy.  If I get a good clear night I'll see if I can see it with my 8" SCT.  From my viewing location, it will only get up to a maximum of 13 deg above the Southern horizon, which for me is pretty light-polluted due to the large city in that direction.  Thanks for posting a great challenge Phil!

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#3 warddl



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Posted 03 November 2021 - 08:28 AM

Fascinating history on this object.  Looking forward to chasing it as soon as I can get to a site with a better southern horizon.  

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#4 dave253


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Posted 05 November 2021 - 07:29 AM

A personal favourite! 
That section of sky is my happy hunting ground; it’s in the darkest part (south), and passes overhead.
The whole area is chock full of galaxies. 

#5 Redbetter


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Posted 09 November 2021 - 04:37 AM

The main problem for this one for most mid latitude northern observers is its low declination.  It is a "tree dodger" at most of my observing sites, reaching only about 15 degrees above the horizon.   This severely limits the observation window and means I am most often observing it between breaks in trees.   It would be much more challenging much above 40 N.  


At such a low declination, the background sky is bright and washed out most places I observe, even if a decent Bortle 3 at altitude.  While it isn't hard to find, only the most transparent nights will yield a good look because of the weak contrast.   I never feel like I am really seeing it the way it was meant to be seen and look forward to trying it from the Southern Hemisphere some day.    


This galaxy makes for an interesting comparison with NGC 247 about 17 degrees to the north.  247 has substantially worse surface brightness, but is just far enough north that the contrast loss ends up being similar.   (NGC 247 has Burbidge's chain.)  


The way I typically do the hop is the form of a grand tour:  NGC 247, then NGC 253 (spectacular), NGC 288 (large globular), Sculptor Dwarf (very low surface brightness), then NGC 300.  I finish up with NGC 55 which is about 1.5 degrees further south and a number of degrees further west.   These are all high value targets in their own right, but each with different character, hampered only by their low positions.  

#6 Eclipsed


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Posted 09 November 2021 - 12:22 PM

This is certainly a tough one for those of us in more Northern locations!


I had two attempts to look for this target on Nov 6th and 7th.  Both evenings were crisp and cool and fairly clear, with decent seeing for my backyard viewing location.  On the first night I could not even find it with my Celestron Evo 8.  On the second night I did locate it but it was so low and inside a bright dome of light from the city south of my home, it was only barely distinguishable using low power eyepieces (APM 30mm was best) . At that time it hadn't reached its maximum elevation of 13 degrees (at maximum, due South it would have been blocked by trees). I used a filter to try and cut the unwanted light out, however it wasn't much help as it also cut out a fair amount of the galaxy light.  Then I tried to capture and image with my ZWO ASI178MC camera attached but it was so poorly defined that i'm not even going to post the image here!!  Part of the issue is that its a fairly large target for my set up.  I may have another go if conditions are just righ.!  Good luck to those who are attempting to find the target!

#7 Jon Isaacs

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Posted 09 November 2021 - 08:04 PM

I've been up at our place in the high desert for the past week and I've looked at NGC300 each night for maybe 20 -30 minutes. I'm using either 16 or the 22. XI see a little more each night but as Red said it's low on the horizon, about 18° for me. I have a clear southern horizon but there's sky glow some small villages across the border in Mexico.


I'm seeing spiral structure but I'm always thinking, "If in were just 10° further south.."


Another nice galaxy the region is NGC134. It's a nice mag 10.3 spiral with the mag 13.1 NGC131 as a companion.



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#8 sgottlieb


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Posted 09 November 2021 - 10:39 PM

I've seen NGC 300 mentioned as a companion with NGC 55, but never as a member of the Local Group (stated in the article).  Any references?


The galaxy is visible in my 15x50 IS binoculars from Northern California as a relatively large, very low surface brightness hazy region, roughly 15' in size.  A star is superimposed on the SW side.


I had an excellent view through a 25" f/5 from Australia with the galaxy high overhead.  Using 187x I logged it as bright, extremely large, irregular, elongated roughly 5:3 WNW-ESE, at least 15'x9'.  Contains a large, brighter core region with a mag 11.5 star at the ENE edge of the core.  A mag 9.6 star is in the halo (along a faint spiral arm), 2.6' SW of center and a mag 10.6 star is superimposed in the outer halo, 5.3' SE of center.


Spiral structure was surprisingly subtle.  A low contrast, broad inner arm extends west from the north side of the core, curls south on the west side and spreads out.  A more obvious inner arm emerges from the south side of the core and sweeps east and north, though the root of the arm is not defined.  The arm passes through a relatively bright and large HII patch/OB association, ~25" diameter, situated 3.9' E of center and loses contrast further north.   A mag 11.5 star is 2.3' further NE in the outer halo of the galaxy. I didn't have time to examine the galaxy at higher power to search for additional H II knots.

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#9 TonyCaf


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Posted 22 November 2021 - 05:49 AM

Time to get out the chainsaw!

#10 John O'Hara

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Posted 30 November 2021 - 11:33 AM



Kelly and I are wintering in Quartzsite, AZ and I'm hoping to try for NGC 300 tonight with my 100ED f/9 refractor.  This galaxy will be 8 degrees higher down her than in Northwest Pennsylvania, so I'm hoping for a good view.  If things work out, I'll probably bring down a bigger scope next year.



#11 John O'Hara

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Posted 01 December 2021 - 07:28 PM

We'll, I'm a day late and a dollar short as Phil has already introduced December's article.  For what it's worth, I did observe NGC 300 last night from a dark site in the KOFA Wildlife Refuge south of Quartzite, AZ.  It was a decent night, with transparency ranging from 7 to 8 out of 10.  What's more, the object was 8 degrees higher than it would have been from my native area in Northern Pennsylvania.  I found the object at 30x in my 100 mm f/9 refractor.  I then increased the power to 69x and found that this dimmed the image too much.  Decreasing to 45x provided the best view.  I could see it with direct vision, but averted vision revealed a round uniform glow about 20' diameter.  A "bright" field star was on the NE edge, and two other faint stars were superimposed, winking on and off with averted vision as the seeing came and went.  It made me wish that I'd brought a larger telescope to Arizona, but cargo space was limited. 



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