World Library  
Flag as Inappropriate
Email this Article

Messier 103

Article Id: WHEBN0000969070
Reproduction Date:

Title: Messier 103  
Author: World Heritage Encyclopedia
Language: English
Subject: Cassiopeia (constellation), Sombrero Galaxy, List of Messier objects, M103, Perseus Arm
Publisher: World Heritage Encyclopedia

Messier 103

NGC 581
Observation data (J2000.0 epoch)
Right ascension 01h 33.2m
Declination +60° 42′
Distance 10 thousand light years (3 kpc[1])
Apparent magnitude (V) 7.4
Apparent dimensions (V) 6.0'
Physical characteristics
Other designations M103

Messier 103 (also known as M103, or NGC 581) is an open cluster where a few thousand stars formed in the constellation Cassiopeia. This open cluster was discovered in 1781 by Charles Messier’s friend and collaborator Pierre Méchain.[2] It is one of the most distant open clusters known, with distances of 8,000 to 9,500 light years from the earth[1][2] and ranging about 15 light years apart. There are about 40 member stars within M103,[2] two of which have magnitudes 10.5, and a 10.8 red giant, which is the brightest within the cluster. Observation of M103 is generally dominated by the appearance of Struve 131,[3] though the star is not a member of the 172-star cluster.[3] M103 is about 25 million years old.[2]


  • Observation history 1
    • Observing with binoculars 1.1
  • References 2
  • External links 3

Observation history

After the discovery of Messier 101, 102 and 103 in 1781, Messier himself had no occasion to carry out more detailed observations of these clusters and included them as a last-minute addition to his catalogue using the data of Méchain.[3][4] In 1783, William Herschel observed M103 and described the region as 14 to 16 pL (pretty large stars) and with great many eS or extremely faint ones.[5] Åke Wallenquist then identified 40 stars in M103 while Antonín Bečvář raised the number to 60. Subsequently Archinal and Hynes determined that the cluster had 172 stars.[3] Admiral William Henry Smyth was the first to see the 10.8-magnitude red giant, citing the double star on Cassiopeia’s knee, about a degree to nf of Delta.

Observing with binoculars

Messier 103 has been rated by the Astronomical League[3] as an easy[6] object to find and the cluster is visible even with the use of binoculars.[3][7] M103 can be seen as a nebulous fan-shaped patch, and optically is about a 6 arcminute circle, or about a fifth the diameter of the full moon. In order to find M103, it is suggested that the observer center their binoculars on Ruchbah or the bottom left star of the visible “W” in Cassiopeia. The cluster will appear as a hazy patch about 1/3 of a field toward 45 Epsilon Cassiopeia.


  1. ^ a b Sanner, J.; Geffert, M.; Brunzendorf, J.; Schmoll, J. (1999). "Photometric and kinematic studies of open star clusters. I. NGC 581 (M 103)".  
  2. ^ a b c d Robert Bruce Thompson [2], M103 (open cluster in Cassiopeia). Accessed online 13 April 2011
  3. ^ a b c d e f "Messier 103: Observations and Descriptions". SEDS. Retrieved 2011-04-13. 
  4. ^ "3 Clusters in Cassiopeia". One Minute Astronomer. Retrieved 2010-04-14. 
  5. ^ "Messier 103". Universe Today. Retrieved 2010-04-14. 
  6. ^ "Messier 103". Perez Media. Retrieved 2010-04-14. 
  7. ^ "The Constellation Cassiopeia". Zimbio. Retrieved 2010-04-14. 

External links

  • Open Cluster M103 @ SEDS Messier pages
  • Open Cluster M103 @
  • Messier 103 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.