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The Sky This Month - September 2007

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Written by Gary Boyle, Ottawa on
Post Date: 
Sun, 2007/09/02

The Winged Horse

Looking like a giant celestial baseball diamond, the Great Square of Pegasus stands proudly in eastern skies. Mythology has it that Perseus the hunter, along with Andromeda who he recently saved from the sea monster Cetus, rode off on this winged beast. As early falls nights slowly announce themselves with earlier sunsets and cooler temperature keeping mosquitoes at bay, telescopes should be working overtime, as Pegasus is peppered with faint galaxies.

As twilight comes to an end, I love to just look up and welcome each star as they introduce themselves, one by one. About an hour after sunset, the faint misty band is glimpsed. Poised overhead is the majestic Milky Way, the glow of millions of our galaxy’s stars. As the sky darkens even more, you cannot help but to stare at this marvel. This haze can be followed as it stretches down to the heart of the galaxy, nestled between Sagittarius and Scorpius.

 

 

With the eleven night observing window from September 5th to the 16th, moonlight will not hamper your all night observing sessions. Every night dishes us a multitude of objects – some bright with detail along with tiny grey smudges. Starting off any observing session is our closest galaxy in Andromeda. At an incredible distance of 2.9 million light years (ly), this prize winner can be spotted with only your eyes from a dark site.

Catalogued M31 or NGC 224, the Andromeda Galaxy is astounding in any instrument from binoculars to large aperture telescope. Flanked by its two satellite galaxies more commonly referred as M32 and M110, M31 measures three degrees or six full moons in width. With moderate to large telescopes, many globular clusters in this distant galaxy can be spotted.

With M31 being almost nine degrees above the bright star Mirach, move down from this star by seven degrees and you will come to the face-on bright galaxy aka M33. List at about the same distance as the Andromeda Galaxy, M33 (located on Triangulum) glows at seventh magnitude and is fascinating to study with a large aperture telescope. There are no less than seven catalogues IC objects embedded in this galaxy.

Moving to the other side of this constellation is the bright and highly resolved globular cluster M15. It rests some 33,600 ly away and is under naked eye detection at magnitude 7.5. Aside from M13, this globular is second in its category on my favourites list. It is moving toward us at 175 km/sec but the sky is not falling yet. At this rate it will reach us in 100 million years.

Dropping down thirteen degrees, you will find another gem just as bright and 3,400 ly farther. M2 is another well resolved globular cluster which contains an estimated 150,000 stars in an area some 175 light years across.

 

 

Venturing deeper in the cosmos, look for NGC 7331 aka the Deer Lick Galaxy. At a decent magnitude of 9.5, it is a wonder Charles Messier did not add it to his popular list. Back in 1959, astronomers witnessed this galaxy lose one of its members in the form of a magnitude 13.5 supernova. Of course it actually blew up some three million years ago. This has been the only event of its kind recorded in that distant galaxy.

Once you finish with this elongated galaxy and feel adventurous, move a half a degree to the west and try to spot Stephan’s Quintet. This is a collection of five closely knit faint members and can be quite a challenge to find. According to the Chandra X-Ray Observatory the four faintest members (A,B,D and E) seem to lie an amazing 280 million ly away while the brightest and largest member in the photo is a foreground object only 35 million ly from us. But if you add component C then we are back to the family of five at that great distance. Surely some of the farthest galaxies you can see in a telescope.

For a completely change of pace, NGC 7772 is a faint but loose open cluster. There seems to be only a dozen members of this group. NGC 7772 is a little more than five degrees west of the square’s corner star Algenib. At a distance of 335 ly, this evolving subgiant is listed as a hot B class star believed to have a surface temperature of 21,500 degrees Kelvin.

Within the confines of the Great Square, lie literally dozens of remote galaxies, too many to mention in this article. You definitely have a few nights work tracking down these objects.

Well we have officially said goodbye to the planets Venus and Saturn as they disappeared into the Sun’s glare. What a great show they put on for us but they will be back soon enough. In the mean time, the king of planets – Jupiter is sinking in the west. With such a low elevation as seen from Canada combined with upper air turbulence, great observations were few and far between.

 

 

We do have three other planets available for your viewing pleasure. Neptune can be spotted in the constellation Capricornus at magnitude 7.8. Any telescope will show a featureless bluish disk which is some 4.4 billion kilometers away and its light takes four hours to reach us. Moving down twenty-seven degrees on the east on the ecliptic is the bluish green disk or Uranus. Although a bit closer at 2.9 billion kilometers, its light travels 162 minutes till it reaches us.

This is of course the year of Mars and also another year of the great hoax. I don’t know how the notion of the red planets will be as large as the Moon when it will be closest but that is utterly false. It will only be a tiny fraction compared to the Moon.

Mars is up around 11 p.m. locally and is a mere four degrees north from Aldebaran – the eye of Taurus the Bull. What a sight seeing this pair climb the eastern sky with the Pleiades not too far away. Mars will be closest to the Earth on December 18th at a distance of 88.5 million kilometers and will be at its brightest on December 24th. Wow – what a Christmas present that will be.

 

 

Object

Type

Magnitude

Coordinates

IC 1465

Open Cluster

 

RA:23h 02m 53.9s  Dec:+16d 34' 59"

IC 1613

Spiral Galaxy

9.0

RA:01h 04m 48.0s  Dec:+02d 07' 00"

IC 5338

Spiral Galaxy

13.0

RA:23h 36m 30.0s  Dec:+21d 09' 00"

M 110

Elongated

8.0

RA:00h 40m 50.3s  Dec:+41d 43' 31"

M 15

Globular Cluster

6.4

RA:21h 30m 23.8s  Dec:+12d 12' 06"

M 2

Globular Cluster

6.5

RA:21h 33m 55.3s  Dec:-00d 46' 53"

M 31

Elongated Galaxy

3.5

RA:00h 42m 42.0s  Dec:+41d 16' 00"

M 32

Round Galaxy

8.5

RA:00h 43m  8.3s  Dec:+40d 54' 31"

NGC 1

Elongated Galaxy

13.0

RA:00h 07m 43.0s  Dec:+27d 45' 37"

NGC 14

Round Galaxy

12.0

RA:00h 09m 13.2s  Dec:+15d 51' 43"

NGC 157

Elongated Galaxy

10.4

RA:00h 35m 12.7s  Dec:-08d 21' 16"

NGC 16

Elongated Galaxy

12.7

RA:00h 09m 31.0s  Dec:+27d 46' 37"

NGC 23

Elongated Galaxy

12.4

RA:00h 10m 19.0s  Dec:+25d 57' 37"

NGC 246

Planetary Nebula

8.0

RA:00h 47m 24.5s  Dec:-11d 50' 16"

NGC 488

Elongated Galaxy

10.2

RA:01h 22m 13.0s  Dec:+05d 17' 34"

NGC 68 / 71

Round/Elong Galaxies

13.1

RA:00h 18m 43.2s  Dec:+30d 06' 36"

NGC 7063

Open cluster

7.0

RA:21h 24m 44.3s  Dec:+36d 32' 03"

NGC 7217

Round Galaxy

10.2

RA:22h 08m 16.1s  Dec:+31d 24' 19"

NGC 7331

Elongated Galaxy

9.5

RA:22h 37m 28.5s  Dec:+34d 27' 25"

NGC 7448

Elongated Galaxy

11.7

RA:23h 00m 30.2s  Dec:+16d 01' 33"

NGC 7465

Round Galaxy

13.0

RA:23h 02m 24.3s  Dec:+16d 00' 34"

NGC 7469

Round Galaxy

11.9

RA:23h 03m 42.8s  Dec:+08d 54' 37"

NGC 7497

Elongated Galaxy

13.0

RA:23h 09m 30.2s  Dec:+18d 13' 35"

NGC 7539

Round Galaxy

13.0

RA:23h 14m 48.0s  Dec:+23d 42' 35"

NGC 7623

Elongated Galaxy

12.4

RA:23h 20m 55.0s  Dec:+08d 26' 40"

NGC 7625

Round Galaxy

12.1

RA:23h 20m 54.4s  Dec:+17d 16' 36"

NGC 7662

Planetary Nebula

9.0

RA:23h 26m 17.5s  Dec:+42d 35' 33"

NGC 7664

Elongated Galaxy

13.0

RA:23h 27m  0.2s  Dec:+25d 06' 36"

NGC 7671

Elongated Galaxy

12.7

RA:23h 27m 42.9s  Dec:+12d 30' 41"

NGC 7673

Elongated Galaxy

12.7

RA:23h 28m  6.3s  Dec:+23d 37' 36"

NGC 7678

Round Galaxy

12.8

RA:23h 28m 54.3s  Dec:+22d 27' 36"

NGC 7712

Round Galaxy

13.0

RA:23h 36m 18.4s  Dec:+23d 38' 37"

NGC 7720

Spiral Galaxy

12.6

RA:23h 38m 54.4s  Dec:+27d 04' 36"

NGC 7722

Round Galaxy

13.0

RA:23h 39m 12.9s  Dec:+15d 59' 42"

NGC 7741

Elongated Galaxy

11.4

RA:23h 44m 18.5s  Dec:+26d 07' 37"

NGC 7742

Round Galaxy

12.5

RA:23h 44m 43.0s  Dec:+10d 48' 43"

NGC 7743

Round Galaxy

11.2

RA:23h 44m 49.0s  Dec:+09d 58' 43"

NGC 7753

Round Galaxy

13.0

RA:23h 47m 30.5s  Dec:+29d 31' 36"

NGC 7769

Round Galaxy

12.1

RA:23h 51m 31.0s  Dec:+20d 11' 42"

NGC 7771

Elongated Galaxy

12.3

RA:23h 51m 48.9s  Dec:+20d 09' 42"

NGC 7772

Faint open cluster

12.1

RA:23h 52m 13.0s  Dec:+16d 17' 42"

NGC 7798

Round Galaxy

12.7

RA:23h 59m 48.8s  Dec:+20d 47' 39"

NGC 7800

Elongated

13.0

RA:24h 00m  1.1s  Dec:+14d 51' 43"

NGC 7814

Round Galaxy

10.5

RA:00h 03m 43.2s  Dec:+16d 11' 42"

NGC 7817

Elongated Galaxy

12.0

RA:00h 04m 25.2s  Dec:+20d 47' 42"

NGC 80 / 83

Round Galaxy

12.1

RA:00h 21m 37.5s  Dec:+22d 23' 41"

Stephan’s Quintet

Galaxy Group

12.7 to 13.6

RA:22h 36m 16.5s  Dec:+33d 59' 26"

 

Until next month. Clear skies everyone

Gary Boyle