Bulletin Board

Latest Website Update [1 Oct 2015] COMING SOON - DSO 169 and a new Object of the Season >> NGC 80 and Arp 65 is our Picture of the Month >> New Galaxies and Double Stars of the Month for October >> New observations of our September Double Star and Galaxies

We have a date for the 2016 Annual Meeting: 18 June 2016.

October 2015 - Picture of the Month

NGC 80 and Arp 65 in the Constellation of Andromeda

NGC 80 and the Arp 65 group of galaxies - Image Courtesy of Makis Palaiologou, Stefan Binnewies, Josef Pöpsel: www.capella-observatory.com

Image was provided courtesy of Makis Palaiologou, Stefan Binnewies, Josef Pöpsel: www.capella-observatory.com.

Interestingly, Owen's covered this group in a previous Galaxy of the Month (November 2012). He used an image from the Digitized Sky Survey, but I think that this one is much better. Worth a read though.

Capella Observatory provide a version of this image in which the galaxies are tagged with their names.

That, and Owen's piece, should make it easier for those thinking of having a go at this one. Good luck.

James Whinfrey - Website Administrator.

Object of the Season (Summer 2015)

Galaxy Pair NGC 1 and 2 in Pegasus

Galaxy Pair NGC 1 and 2 in Pegasus will be announced in DSO 168, and the results will be published in DSO 170.

The optical galaxy pair NGC 1 and NGC 2 in Pegasus: NGC 1 is the northern object - Image Courtesy of Sloan Digital Sky Survey (SDSS) This image was supplied by the Sloan Digital Sky Survey (SDSS). NGC 1 is the northern object.


Position (2000)
0 07 15.9 +27 42 32 (Peg)
Visual magnitude
12.9 mag
1.7' x 1.2'
206 Mly
Other Designations
GC 1, UGC 57, MCG 4-1-25, CGCG 477-54, KCPG 2A, PGC 564


Position (2000)
0 07 17.1 +27 40 43 (Peg)
Visual magnitude
14.2 mag
1.0' x 0.6
347 Mly
Other Designations
GC 6246, UGC 59, MCG 4-1-26, CGCG 477-55, KCPG 2B, PGC 567

Wolfgang Steinicke - Nebulae and Clusters Section Director

October 2015 - Double Star of the Month

STF 2816 (21 38 57.62 +57 29 20.5) which sits within the cluster Trumpler 37 (and the HII region IC 1396) and is a multiple star with three stars visible to the small aperture.

AC are stars of magnitudes 5.7 and 7.5 separated by 12" in PA 120 and with little motion visible. The primary is a very hot star of spectral type O6f. Some 20" away in PA 338 is a further star (D) of magnitude 7.8. This in turn has a 13.2 mag comes at 351 degs and 55". In 1889, using the Lick 36-inch refractor, S. W. Burnham added a 13.3 star to A at a distance of 1".7. At the highest angular resolutions A is double again with a companion at a distance of 0".1 and it is also a double-lined spectroscopic binary with a period of 3.7 days so it seems likely that this is a very close triple.

For the binocular user, the stars that make up the wide pair of pi1 and pi2 Gruis make a splendid sight. They lie about halfway between alpha and beta Gruis and a degree north of that line.

The brighter of the two is pi1 Gru (22 22 44.2 -45 56 52.61) at V = 5.62. This is a F3 star which is a giant or sub-giant and which has a large annual proper motion. Its distance is correspondly small - 130 light years. Some 269" east and slightly north is pi2 at V = 6.55 but extremely red in colour. It is a member of the rare spectral class S and has a (B - V) index of 2.1. Looking at it on the POSS images it appears slightly brighter than pi1 but when the 2MASS survey image is examined, its overwhelmingly bright image practically obliterates that of its companion.

Both stars are double and both were discovered by Robert Innes. Pi1 is I 135 - the companion is a GO dwarf, magnitude 10.7, distant 2".5 in PA 200, although observations of the system with VLTI show a spiral-shaped arc of emission which may be due to orbital motion of this dwarf and indicates the possibility of a third star, much closer in with a period of less than 10 years. Pi2 is I 382 where the 11.4 mag companion has moved from a separation of 4".6 to 11" over the course of a century, due to the large motion of A.

Bob Argyle - Double Star Section Director

October 2015 - Galaxy of the Month

NGC 7541 in Pisces

This interactive image of the NGC 7541 / NGC 7537 pair of galaxies was provided by the Sloan Sky Survey using Aladin Sky Atlas. We've also provided a finder chart for the group too.

The galaxy pair NGC 7541 and NGC 7537 in Pisces were both discovered by William Herschel in 1785, although NGC 7541 may also be the nebulous object which was seen by Horace Tuttle in 1875 whilst looking for Encke’s comet and later catalogued as NGC 7581. They are both located within the circlet of Pisces.

NGC 7541 and NGC 7537 are probably a true galaxy pair, although this is not 100% certain. They are both spiral galaxies at a distance of around 33 Mpc. NGC 7537 is classed as Sbc and NGC 7541 as SBc i..e. a barred spiral. Both galaxies are see close to edge on. At this distance NGC 7537 would be about 94000 light years across and NGC 7541 about 145000, so comparable in size to our Milky Way galaxy.

NGC 7541 was home to the type Ia supernova 1998dh. Not to be outdone NGC 7537 was home to supernova SN 2002gd. This would appear to have been a Type II-p.

It would appear from X-Ray observations that NGC 7541 is currently undergoing a period of high star formation. Whether this is in anyway related to a gravitational interaction with NGC 7537 is questionable.

In 1999 astronomers combined images from two different camera on the Hubble space telescope to try and estimate the ages of the stars in the central regions of NGC 7537. This study appears to suggest that the bulges of spiral galaxies formed in a relatively short time in the early universe. This may have happened by the collapse of a single large gas cloud or by the merger of large star clusters.

Both these two galaxies appear in NSOG Vol 1 and would appear to be visible in telescopes in the 20-22cm category, although instruments with a larger aperture will be required to see much detail. Both galaxies are also described in Luginbuhl and Skiff’s Observing Handbook and Catalogue of Deep Sky objects as reasonable in 25cm but easier with 30cm. NGC 7537 is fainter of the two and may require a larger aperture to be sure of.

Owen Brazell - Galaxy Section Director

Deep-Sky Observer (DSO) No 153 - Free Sample

DSO153 Cover

This free journal is DSO 153 from 2010. You can download it as a PDF file onto your computer by right clicking the link below and choosing either 'Save Target As' or 'Save Link As'...

Download DSO 153 (2MB PDF file)

Clear Skies Observing Guides (CSOG)

Courtesy of Victor van Wulfen.

Clear Skies Observing Guides Banner

Webb Deep-Sky Society member Victor van Wulfen produces the CSOG. He's recently relaunched the website with version 2.1, so now would be a good time to take a look.

The Brightest Planetary Nebulae Observing Atlas - 2nd Edition

Massimo Zecchin has just completed the 2nd Edition of an atlas of planetary nebulae observed with small apertures and from suburban locations, entitled: "The Brightest Planetary Nebulae Observing Atlas".

Massimo has kindly made the atlas is freely available in two versions, Black (for display) and White (printer friendly with the images in negative).

The 2nd Edition contains:

  • Six additional objects.
  • Data of visual magnitude, central star magnitude and object size from the Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (SEC catalogue) and in a few cases from the Saguaro Astronomy Club database (SAC catalogue).
  • Calculated surficial brightness for any object (in magnitude per square arcsec).
  • Six additionaltables showing the objects sorted by magnitude, surficial brightness, size, central star mag, constellation and declination.
  • A general position map.

Either version of the atlas can be downloaded as a PDF file onto your computer by right clicking the respective image above and choosing either Save Target As or Save Link As...

Please note that the Black version is 14MB and the White version 10MB