The Sculptor Galaxy

The “Sculptor Galaxy” NGC 253, also known as the “Silver Coin Galaxy”, is a bright local spiral galaxy, smaller than the Milky Way and only 12,000,000 light years distant.

The apparent width of the galaxy is about one lunar diameter. You could spot it with binoculars – but it looks better with a Skywatcher telescope. With a ZWO camera. 

Its circular disc is about 12° from the edge-on position and it has a concentrated central nucleus and mottle-textured dust lanes & dark patches.

It is located only 2° from the South Galactic Pole.

The pair of foreground bright stars adjacent are:

HD 4555: (magnitude 9.3) 247 light years from the Solar System; and;
HD 4572: (magnitude 8.9), 510 light years from the Solar System


Object Details:

Designation:  NGC 253, Caldwell 65
Constellation: Sculptor
Visual magnitude:   +7.0
Apparent size:  26.8′ x 4.6′
Diameter:   94,000 light years.
Distance:    12 million light years.
Altitude during exposure:   79° above eastern horizon.
Astrometry overlay image:  All the details at: Astrometry.net


Whilst compiling my blog posts, I often refer to my astronomy reference books, including the three volume Burnham’s Celestial Handbook. Written half a century ago by Robert Burnham Jr., this masterpiece is still a very useful tool which is highly recommended and is still available from Dover Publications Inc.

Below is a photograph of NGC 253 reproduced from volume 3 of the book for comparison. It was taken by the 100 inch telescope at Mt Wilson. That instrument had 455 times greater light gathering aperture than my 4.7″ diameter telescope!

burnhams-ngc-253-lowell-observatory-e1570866242542.jpgImage: Mt Wilson Observatory/Burnham’s Celestial Handbook 

So the images which small modern amateur telescopes can take are, at the very least, comparable to those which were taken by the world’s largest telescopes fifty or sixty years ago. That is mostly due to developments in camera technology and I have no doubt that since taking that image, Mt Wilson Observatory took advantage of modern photographic equipment and techniques too.

._.

One thing leads to another and I found myself web-surfing to this page which tells the rather tragic story of the author of Burnham’s Celestial Handbook, Robert Burnham Jr.

Apart from writing this epic reference manual, Burnham took part in the discovery of: six comets; 1,500 asteroids; 9,000 high-motion stars; 2,000 new white-dwarf suspects; and thousands of new proper-motion stars.

Sadly, this high achieving astronomer’s story did not end well. After leaving Lowell Observatory, he became reclusive, went into decline and earned an income from selling paintings of cats.

He died prematurely at the age of 61 and it was another two years before his family even learned the news.


Blog ends here.

All the technical stuff follows:

Image:

Exposure:  60  x 90 sec  =  90 min.
Gain:  92.
Date:  2019-10-03.
Location:  outer suburban.
Moon: 5.2 days, 28% waxing crescent.
Conditions:  clear.
Sky:   0.71 e/pixel/s .


Processing:

Image acquisition:  SharpCap.
Method: Live stacked.
Darks: 6x.
Image post-processing:  GIMP.
Cropping: yes.

 

 

Gear:

Telescope: SkyWatcher Esprit  Type: 120ED triplet refractor
Focal: 840 mm F/7 Mount: SkyWatcher EQ6-R Pro
Camera: ZWO ASI 071 MC Pro
Type: CMOS 28.4mm 16 Mpx
Optical aids: Flattener: Y; filter: LP Guiding: Yes
Polar aligning: QHYCCD PoleMaster Polar Error: 53”

Geek Log:

[ZWO ASI071MC Pro]
Debayer Preview=On
Pan=0
Tilt=0
Output Format=FITS files (*.fits)
Binning=1
Capture Area=4944×3284
Colour Space=RAW16
Hardware Binning=Off
Turbo USB=40
Flip=None
Frame Rate Limit=4 fps
Gain=92
Exposure=90
Timestamp Frames=Off
White Bal (B)=50
White Bal (R)=53
Brightness=16
Temperature=-14.1
Cooler Power=100
Target Temperature=-20
Cooler=On
Auto Exp Max Gain=300
Auto Exp Max Exp M S=30000

Auto Exp Target Brightness=100
Mono Bin=Off
Anti Dew Heater=Off
Banding Threshold=35
Banding Suppression=0
Apply Flat=None
Subtract Dark=C:\Users\Roger\Desktop\SharpCap Captures\darks\ZWO ASI071MC Pro\RAW16@4944×3284\90.0s\gain_92\dark_6_frames_-11.7C_2019-10-03T09_33_50.fits
#Black Point
Display Black Point=0
#MidTone Point
Display MidTone Point=0.5
#White Point
Display White Point=1
TimeStamp=2019-10-03T14:07:10.1452809Z
SharpCapVersion=3.2.6086.0
TotalExposure(s)=5400
StackedFrames=60

Image © Roger Powell

9 Comments

    1. Thanks for looking. Burnham’s three volume handbook is a unique work, which passes the test of time. I guess there are many people out there who have difficulties facing the world around them. We just don’t get to read their stories.

      Like

  1. It is so interesting to learn that background. In Canada, this is Thanksgiving weekend, so I am grateful to have access to all your remarkable photos and blogs. Thank you so much for all the postings. Fran

    Like

  2. Great image, extraordinary, in fact, with detail enough to make you wonder about all those tiny pieces of light, from 12 million years ago.

    What a tragic story of Mr. Burnham. A brilliant mind trapped by a serious personality disorder, from every indication of the linked narrative.

    Liked by 1 person

    1. Thanks, Paul.

      The detail in NGC 253 is fascinating and – as you say – it is remarkable that it is maintained after 12 million years of light travel.

      I’m glad you looked at the Burnham link. You summed him up better than I could.

      Liked by 1 person

      1. It was a little hard to read the article, because as a shy person myself, I know a number of the ancillary characteristics attributed to Mr. Burnham could be applied to me. But there’s a line between extreme shyness and lacking the ability to function in society, and based solely on the article, he was clearly on the latter side.

        Not to say this in any accusatory way to anyone who was close to him, but as a far-off observer, one wonders what his life would have been like if someone early on recognized his gifts, as well as his challenges, and took measures to ensure he was taken care of throughout his life. This is probably easier to hypothesize 60+ years later, for despite the Cold War context and later the space race being prominent in the American collective mindset, astronomy just wouldn’t have been seen as a practical pursuit, as the article alludes, much like it is still viewed today by most.

        Could he have been a Carl Sagan-like rock star in astronomy? Probably not. But it’s clear to me that despite his relatively limited and now distant contribution, he was regarded extremely well by those who knew him and his works, and they were surprised he did not contribute more to the field. That we’re even discussing the man in 2019, nearly 30 years after his death, shows the impact he had, and the great potential never realized.

        Liked by 1 person

      2. I was one of those who had once thought he was the magazine editor (either Sky & Telescope or Astronomy magazine, can’t recall which) of the same name.

        I guess Burnham was more of a Clyde Tombaugh than a Carl Sagan. He even worked at the same observatory where Tombaugh discovered Pluto. His Celestial Handbook contains a timeless treasure trove of data which is still relevant today.

        I wonder, if it had been me, whether I would have taken on the job of janitor which was on offer to him when his project was defunded, on a temporary basis – in the hope that more funding could be available at a later date.

        As you say, one would certainly hope that these days more recognition might be given to assisting people in his circumstances.

        Like

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