The American Association of Amateur Astronomers

Serving the Amateur Astronomy Community ONLINE since 1996

The Constellation Home Page

AstroMax
The AAAA
Online Store

Home

Search AAAA

The AAAA Universe
Start Here

AstroMax
The AAAA Online Store

Membership
Join the AAAA

Control Center
Site Table of Contents

AAAA Members
  Reports and Activities

FAQ
Frequently Asked Questions

Links
to Astronomy Sites

News from the AAAA
Press Releases and News Updates

An Overview of Astronomy
A Concise Guide to the Universe

The Solar System
Planetary Data Page

The Constellation 
Home Page
Data, Myths and Background

Arp Peculiar Galaxies
A CCD Image Gallery

The American Astronomer 
The AAAA  Newsletter Online

Observing Programs
from the  Astronomical League 

Club Discount
on Magazine Subscriptions

Partnerships
Members of the AAAA Team

The American Association of Amateur Astronomers 
AAAA Mission Statement

Special Offer
A Primer for Beginning Astronomers

FREE
Astronomy Information from Sky&Telescope via Electronic Mailing List

AL Observing Programs in PDF Format

FREE
AL Observing Programs in Adobe Acrobat PDF Format

FREE
Join the AAAA's FREE Online Discussion Group, Hosted by Yahoo's eGroups Service

AAAA 
P.O. Box 7981
Dallas, TX 75209-0981

http://www.AstroMax.com
aaaa@AstroMax.com

Formerly Corvus.Com

 

Learn the Constellations
The First Light Astronomy Kit from David Chandler Company
Buy it Now or 
Find Out More

 

The American Association of Amateur Astronomers

Learn the Constellations
The First Light Astronomy Kit from David Chandler Company

 Buy it Now or Find Out More

The Constellation Sagittarius - The Archer

Mythology: 
Sagittarius - The Archer 

While Cronus, father of Zeus, was courting the mortal woman Philyra, he assumed the form of a stallion to avoid the fury of his jealous wife, Rhea. From this union was born Chiron, the most famous of centaurs and a skillful archer. Although centaurs, creatures who are part man and part horse, were generally savage and cruel, Chiron was wise, gentle and good. As the teacher of several famous heroes, he educated the boys about the mysteries of life. One fated day, Chiron was mistakenly slain by his student, Hercules. Realizing the wound was incurable, Chiron begged Zeus not to deprive him of immortality. Pitying his half-brother's predicament, Zeus granted the request and located Chiron in the sky as the constellation Sagittarius, where The Archer stands with bow and arrow for all time.

Sagittarius is a summer constellation. For Northern Hemisphere observers, it can be seen floating above the southern horizon during the summer months from June through August and into early September. However, by September, it is beginning to set by sunset.

Sagittarius is commonly called "the teapot" because the shape of the stars seems to look like a teapot to modern observers. However, the ancient Greeks and Romans, who named the constellation, thought it looked like a centaur shooting a bow and arrow into the heart of Scorpius, the scorpion. Sagittarius mean Archer.

And easy way to find Sagittarius would be to find the Milky Way overhead in summer. Follow it to the southern horizon, and you should find Sagittarius.

As with all constellations, Sagittarius is best seen in a dark sky outside the city. However, because its stars are relatively bright, you should be able to make out the basic shape even when the moon is up.

Sagittarius is the happy hunting ground of the summer observer. Within it lies the very heart of the Milky Way itself, providing vistas which are unparalleled in grandeur and diversity. Observers at a southerly latitude are provided with views unattainable by their more northerly brethren, for whom this constellation lies just along the southern horizon. Southern Hemisphere observers have the best view, since Sagittarius flies straight overhead when viewed from Australia, South America, and southern Africa..

Diffuse nebulae abound in this region, along with their associated open star clusters. As globular clusters orbit around the center of our galaxy, many of this beautiful class of objects are also found within its boundaries. 

The August 1993 issue of ASTRONOMY magazine highlighted planetary nebulae in this region, and I highly recommend consulting that article. Here, I will only be able to highlight objects which I found to be particularly fascinating, and will almost assuredly leave out somebody's favorite object. The truth is, this constellation is worthy of several night's observing, and not just for Messier objects. Many beautiful non-Messier objects can be found by examining a star chart and pointing a telescope.

SAGITTARIUS

M8 and M20 - Photo copyright by Ed FlaspoehlerM8 and M20 dominate the summer Milky Way, standing out boldly against the dust and star clouds of the Galactic Center in Sagittarius. Part of M24 can be seen poking in on the upper left, and open cluster M23 is at the top center. Saturn, a non-stellar interloper, shines brightly to the left of M20 in this 200-mm photo made on Konica 3200 film at the Prude Ranch during the 1988 Texas Star Party.

M-8 - The Lagoon Nebula. One of the finest cluster/nebula combinations in the sky. The large, scattered open cluster lies at the eastern edge of a large, swirling cloud of nebulosity. The nebula has obvious dark lanes and looping patterns, which in long exposure photography are shown to dense star forming regions. This is a fine sight in almost any telescope, and is easily seen by both the naked eye and in binoculars.

M-20 - The Trifid Nebula. This often photographed nebula is rather faint in small telescopes, but in moderate size instruments shows a circular patch of light surrounding a double star. Tis patch of light is more or less equally divided by three intersecting dark lanes meeting near its center. A fainter region of reflection nebulosity can be seen to the north.

M-17 - The Omega or Swan Nebula. This is one of my favorite objects in this region. This bright nebula looks like a check mark or swan floating in a heavenly pond. It consists of a curving arc of nebulosity connected to a straighter bar shape. The bar portion shows a lot of intricate mottling and streaks. Photography shows this region to be only a small part of a larger, billowing nebulous region.

M-22 - This is one of the finest globular clusters in the sky visible from northern latitudes. It is large, about 15-20' in diameter, and is rather loosely gathered, allowing us to resolve many individual stars across its face. Some consider this globular to be second only to Omega Centauri in beauty.

M-24 - The Small Sagittarius Star Cloud. This is a large, disconnected portion of the Milky Way. The best view comes in binoculars, which show countless stars and some obvious dark streaks along its length. NGC 6603, which some authors claim erroneously to be M-24, lies in its northeastern section. This is a small, tight open cluster bearing no resemblance to Messier's original description.

NGC -6522 and NGC6528 in Sagirttarius - Photo copyright by Ed Flaspoehler

NGC 6522 and NGC 6528 - Anyone who has observed with me will not be surprised by my inclusion of these two faint globular clusters in this article. Every time I observe in the summer, my telescope is at some time pointed at these objects. They are small and moderately faint, but lie within the same field of view of a low power eyepiece in a highly populated region of the Milky Way. The longer they are observed, the more background stars become visible, producing a grainy backdrop for these two twin globulars. A great deep sky double!

NGC 6520 and B86 - Another of my personal showpiece objects in Sagittarius, NGC 6520 is a small, rather tight gathering of about twenty stars placed right next to a similarly sized dark nebula, B86. The proximity of the cluster seems to accentuate the darkness of the nebula and make it appear as a hole in the sky, definitely darker than the surrounding region. This dark nebula is commonly known as the Ink Spot because of this.

Article © Copyright Rick Raasch
Photos
© Copyright Edward P. Flaspoehler, Jr.

Messier Objects in Sagittarius

Con

Messier

Type

R.A.

Dec.

Mag.

Size

NGC#

Sgr

M8

Cluster/Nebula

18h 3.1

-24d 23

5.0

60' X 35'

6523

Sgr

M17

Cluster/Nebula

18h 20.8

-16d 11

7.0

11.0'

6618

Sgr

M18

Open Cluster

18h 19.9

-17d 8

8.0

9.0'

6613

Sgr

M20

Cluster/Nebula

18h 2.3

-23d 2

5.0

28.0'

6514

Sgr

M21

Open Cluster

18h 4.6

-22d 30

7.0

13.0'

6531

Sgr

M22

Globular Cluster

18h 36.4

-29d 54

6.5

24.0'

6656

Sgr

M23

Open Cluster

17h 56.8

-19d 1

6.0

27.0'

6494

Sgr

M24

Open Cluster

18h 18.4

-18d 25

11.5

2 Degrees

6603 *

Sgr

M25

Open Cluster

18h 28.8

-19d 17

4.9

40.0'

4725

Sgr

M28

Globular Cluster

18h 24.5

-24d 52

8.5

11.2'

6626

Sgr

M54

Globular Cluster

18h 55.1

-30d 29

8.5

9.1'

6715

Sgr

M55

Globular Cluster

19h 40.0

-30d 58

7.0

19.0'

6809

Sgr

M69

Globular Cluster

18h 34.4

-32d 21

9.0

7.1'

6637

Sgr

M70

Globular Cluster

18h 43.2

-32d 18

9.0

7.8'

6681

Sgr

M75

Globular Cluster

20h 6.1

-21d 55

9.5

6.0'

6864

* NGC 6603 is only part of M2

The Lagoon and Trifid Nebulae. Photo copyright by Ed Flaspoehler

Another view of the Lagoon and Trifid Nebulae, photographed on August 14, 1999, using Celestron 80-mm f/5 spotting scope. Five minute exposure on Fuji Color 800 film. Photo copyright by Ed Flaspoehler.

The Constellation Home Page
Sponsored by the American Association of Amateur Astronomers.

EDITOR: Edward P. Flaspoehler, Jr.

Help support the development of the Constellation Home Page.
Become a member of the American Association of Amateur Astronomers.
To join, send your name and address along with y our check for $20.00 ($25.00 family)
to the following address.

LOGO: American Association of Amateur Astronomers

AAAA
P.O. Box 7981
Dallas, TX 75209-0981

Web Page: http://www.astromax.org
E-mail:
aaaa@astromax.org

Unless otherwise indicated:
All Content © Copyright 1998 by The American Association of Amateur Astronomers
All rights reserved.

Go to Top of Constellation Home Page


Home ] The 88 Astronomical Constellations ] The Winter Constellations ] The Spring Constellations ] The Summer Constellations ] The Autumn Constellations ] The Southern Constellations ] The 12 Zodiacal Constellations and the Signs of the Zodiac ]


Tell Your Friends the Benefits of Joining 
the American Association of Amateur Astronomers!

Observing Awards. Quarterly Newsletter.
Astronomy News and Special Publications.
Club Discounts on Astronomical Publications.
Full Membership in the Astronomical League.

AL Logo
The American Association of Amateur Astronomers is a Member Society of The Astronomical League

 
INTERNATIONAL 
DARK-SKY ASSOCIATION


Friends of 
McDonald Observatory


SEDS - Students for the Exploration and Development of Space


Planetary Society Member

 

Join the American Association
of Amateur Astronomers.

Use your credit card  
or send your name and address along with your check for $20.00 ($25.00 family) 
made payable to AAAA, to:

AAAA
P.O. Box 7981
Dallas, TX 75209-0981

Visits to This Web Site:  Hit Counter