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Deepsky Objects in Andromeda


Introduction

One of the major autumn constellations is Andromeda. It holds several beautiful deep sky objects for telescopes and binoculars. With the help of this "focus on" you should be able to locate and observe these objects. The basic data for the objects are listed in the table at the end of this article. The map below provides you with a general overview of the location of the different objects discussed in this article.



Overview of Objects in constellation Andromeda

Credit and © Software Bisque, “TheSky for Macintosh”



Gamma Andromedae (Almach)


We start our journey at Almach, or γ (Gamma) Andromedae, one of the most beautiful double stars in the autumn night sky. There are two main components, A (mag 2.3) and B (mag 5.5). The blue-green B component is separated from the yellow A component by 9.8″in a position angle of 63°. The contrasting colours are very easy to detect when you turn your eyepiece view just a little out of focus. Since F.G.W. Struve has recorded it for the first time in 1830, there has been no change in position angle or separation.

From Gamma Andromedae we go to our next stop, NGC 891.


NGC 891 (Caldwell 23)


About 3.5° to the east of Gamma Andromedae you will find NGC 891, an edge-on type Sb galaxy, discovered by Caroline Herschel in August 1783.

With your finder scope centred on Gamma Andromedae, move your telescope to the east in the direction of M34 until the double star is almost on the western edge of the field of view of your finder scope. If your finder scope has a field of 4° degrees or more you should be able to see a triangle of stars of magnitude 5.8, 6.7 and 6.9 in the eastern half of your finder scope (see map below). NGC 891 lies close to the mag. 6.7 star.


Finder chart NGC 891

Finderchart NGC 891 with stallar magnitudes south is up, west is to the left.

Credit and © Software Bisque, “TheSky for Macintosh”

NGC 891

NGC 891


This galaxy, with a visual magnitude of 9.9 has a surface brightness of 13.7, which is low. It is not an easy object for small telescopes. Under dark skies, O' Meara (The Caldwell Objects) could see it with averted vision in his 4 inch telescope at 23x. With direct vision it vanished immediately. According to Harrington (The Deep Sky, an introduction) a 200 mm telescope should show the galaxy at a 100x. The galaxy is oriented north-northeast to south-southwest.



NGC 752 (Caldwell 28, Collinder 23, Melotte 12)


From NGC 891 we go back to Gamma Andromedae. About 4° to 5° south-southwest of Gamma Andromedae you will find an asterism looking like a golf putter (Harrington's Star 14, based on an idea of John Davis, Armherst, Massachusetts).

On the image to the right (viewfinder with a field of view 4°) you see the golf club upside down, with the small triangle of stars forming the head of the club. NGC 752 is the ball, which lies in front of it.

This type III 1 m cluster is very rewarding for those who observe with big binoculars or rich-field telescopes, using low power. It's 60 stars ranging from the 8th to 12th magnitude lie scattered over an area of 75′. Small chains and irregular clumps of stars can be detected, as well as a large number of double stars.

Take your time while observing this fine open cluster, before moving on to the next deep sky object on our trip through Andromeda, NGC 404.


NGC 752 (Caldwell 28, Collinder 23, Melotte 12)

NGC 752 and "the golf putter"
south is up , west is to the left.

Credit and © Software Bisque, “TheSky for Macintosh”


NGC 404 (Mirach's Ghost)


Our next stop is NGC 404. It is very easy to find its location, but once your there, it is much harder to "see" this lenticular galaxy.

First let's find out how to locate NGC 404. Use the map with the general overview at the top. From NGC 752, go back to γ (Gamma) Andromedae. Then move to the west to Mirach or β (Beta) Andromedae. With a low power eyepiece in place, centre Mirach in your field of view. NGC 404 is located about 6.4' Northwest of Mirach . Use higher power to remove Beta Andromedae from your field of view if you don't see NGC 404. You now should be able to detect it, however this object can be invisible one time and very obvious the next. Take your time and use averted vision.

I visited Mirach maybe 10 times until September 2002, hoping to see NGC 404 from my backyard (visual magnitude 5 maximum). The first 9 times I did only see it once, using averted vision and Mirach removed from the field of view. I almost gave up on it.

Then, at the end of September 2002 after a day with steel blue skies, we had a very transparent night. I wanted to observe M31 and pointed my finder scope at Beta Andromedae to go up to M31 from there. I just happened to look through my low power eyepiece while Beta Andromedae was centred in the field of view. I had a large smudge on my eyepiece, at least that's what I thought it was. But it wasn't a smudge; it was NGC 404 in its full glory, at least 4’ in diameter, with direct vision, and the yellowish Mirach in the same field of view.
I couldn't believe it. I had been visiting this location for nearly a dozen times, and just got a glimpse of it once. And now there it was, just like that. A great sight! This proves that not only seeing and transparency can be very important, but also the perseverance of the observer. The reward I got for trying again and again was well worth the effort.


M 31, M 32, M 110


To visit M 31 (our galaxy’s closest neighbour) and its two companion galaxies M 32 and M 110, we have to return to Beta Andromeda. From there go 4° north to μ (Mu) Andromeda, a star of magnitude 3.8. Then go further north about 3° to ν (Nu) Andromeda, a 4.5 magnitude star. Just 1° northwest of Nu Andromeda you will find M 31, the Great Andromeda Galaxy, the largest galaxy of the Local Group.
Even under suburban skies you should be able to see it with your naked eyes, as a 1° fuzzy patch of light. If you live in an area with heavy light pollution, try to find it with binoculars (or your finderscope).

Because M 31 is at least 3° wide, it is best viewed with big binoculars or rich field telescopes, which produce low power magnifications in combination with wide fields of view.

Study this object carefully. Under dark skies, you can see different features like dark lanes (4-8 inch telescope), a bright cloud of stars (NGC 206, 8-10 inch telescope) and some globular clusters (12-14 inch telescope) in this galaxy. According to Kepple and Sanner (The Night Sky observers guide) at low power (40x) a deep-sky filter reveals many light or patchy areas along the length of the arms of this spiral galaxy.


M31, M32, M110

M31. M32 and M110


M 32 (NGC 221), a dwarf elliptical galaxy, can be found at 25′south of the core of M 31. Visually (in my telescope) it looks like a slightly oval smudge of light, not bigger than 1′or 2′in diameter. M 110 (NGC 205), an elliptical galaxy type E5, can be found about 45′to the northwest of the bright core of the Great Andromeda galaxy. In my 200mm telescope it looks like a slightly elongated ellipse of 5′x 2′. I once have observed M 31 through a rich-field telescope, together with M 32 and M 110 in the same field of view. A sight to remember!



Frederici Honores Asterism


Before we go to our last object in this “Focus on”, NGC 7662, we will visit an asterism that lies very close to this planetary nebula, the Frederici Honores asterism (from Peter Birren's Deepsky Viewing List and Field Book for small Telescopes and Binoculars).
This asterism is a part of an obsolete constellation, called “Friedrichs Ehre” or Honores Frederici, also known as Gloria Frederici or Gloria Frederika. This constellation was created at the end of the 18th century by Johann Ellert Bode to honour Frederick II the Great of Prussia. It was created from stars that belonged to Andromeda and Lacerta. After a few years the constellation disappeared again and the stars in the asterism returned to Andromeda.

The constellation of Gloria Frederici represented a sword, feather and some branches of laurel. The four stars in the hilt of the Sword formed the 2° wide Y-shaped Gloria Frederici asterism, Ι(Iota), κ(Kappa), λ(Lambda) and ψ(Psi) Andromedae. You can find these four stars on the the general overview map at the top.


Frederici Honores Asterism

The Honores Frederici constellation

Source unkown


The first three stars are all of the 4th magnitude, and Psi Andromedae has a magnitude of 4.9, so under dark skies the asterism is visible to the naked eye. To find the Frederici Honores Asterism, first go to α (Alpha) Andromedae, the star on the northeastern corner of the Great Square of Pegasus. Then go north about 16° to end in the middle of the Y-shaped asterism. Once you have located this asterism, our last object in this journey through Andromeda, NGC 7662, can be found very easily.



NGC 7662 (Caldwell 22, The Blue Snowball)


We end our journey in Andromeda with the Blue Snowball, my favourite autumn planetary nebula. To find it, take the Honores Frederici asterism as a starting point. From Iota, the southernmost star of the asterism, start moving in western direction towards Ο (Omicron) Andromedae. About two degrees from Iota you will find NGC 7662, the Blue Snowball.

Once you’ve found NGC 7662, try all magnifications and filters you have. It takes high magnifications very well. The UHC filter makes the view much better, but with the OIII, NGC 7662 becomes a bright round ball of light, about 20″in diameter. I could not detect the bluish-green colour, from which it got it’s name, “the Blue Snowball”, but that is probably caused by the fact that I have to observe from a light polluted area.

For a detailed observing report follow this link




 Sketch of NGC 7662 (Caldwell 22, The Blue Snowball)

NGC 7662 at 133x, FOV 122′

Sketch by M.M.H. Heijen



OBJECT
Type
RA
DEC
SIZE
Mv
SB
SA








M 110
Gal
00h40.4m
+41°41′
19.5′x12.5′
8.1
13.9
4
M 31
Gal
00h42.7m
+41°16′
185′x 75′
3.4
13.6
4
M 32
Gal
00h42.7m
+40°52′
11.0′x7.3′
8.1
12.7
4
NGC 404
Gal
01h09.4m
+35°43′
6.1′x6.1′
10.3
14
4
NGC 752
OC
01h57.8m
+37°41′
50'
5.7
-
4
Gamma Andromedae
DS
02h03.9m
+42°19′
-
4.7
-
4
NGC 891
Gal
02h22.6m
+42°21′
13.5′x2.8
9.9
13.7
4
NGC 7662
PN
23h25.9m
+42°33′
30″
8.3
-
4
Frederici Honores Asterism
AST
23h43.0m
+46°00′
3.2° x1.3°
-
-
4

Type: Type of Object
Gal
Galaxy
OC
Open cluster
PN
Planetary Nebulae
DS
Double star
AST
Asterism
RA Right Ascension
DEC Declination
Size Size of the objects in
degrees (°)
arc minutes (′)
arc seconds (″)
Mv Visual Magnitude
SB Surface Brightness
SA Map number of SkyAtlas 2000



Bibliography

  • Objects in the Heavens by Peter Birren
  • The Nightsky Observers Guide Volume 1 by Kepple and Sanner
  • Deep Sky wonders by Walter Scott Houston
  • Deepsky Companions: The Messier Objects by Stephen James O' Meara
  • Deepsky Companions: The Caldwell Objects by Stephen James O' Meara
  • Star Hopping by Robert Garfinkle
  • The Deep Sky by Philip S. Harrington
  • Burnham's Celestial Handbook by Robert Burnham Jr.
  • Atlas Celeste de Flamsteed by John Flamsteed (1776)
  • Atlas der Sternbilder (German) by Slawik and Reichert
  • VVS Deep-Sky Atlas (Dutch) by L. Aerts and L. Vanhoeck
  • SEDS the NGC catalogue by Hartmut Frommert
  • The AAO image pages



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