Astronomy:NGC 7243

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NGC 7243
NGC 7243
Observation data (J2000.0 epoch)
ConstellationLacerta
Right ascension 22h 15m 16.0s[1]
Declination+49° 50′ 07″[1]
Distance2,864 ly (878.0 pc)[2]
Apparent magnitude (V)+6.4[3]
Apparent dimensions (V)30.6[4]
Physical characteristics
Mass348 to 522[5] M
Estimated age(2.5±0.5)×108 years[5]
Other designationsCaldwell 16, Cr 448[6]
See also: Open cluster, List of open clusters

NGC 7243 is an open cluster of stars in the northern constellation of Lacerta. Alternatively, it has the designation Caldwell 16 from the Caldwell catalogue. This cluster was discovered on September 26, 1788 by German-English astronomer William Herschel.[7] It shines at magnitude +6.4, and is located near the naked-eye stars Alpha Lacertae, 4 Lacertae,[3] an A-class double star, and planetary nebula IC 5217.[8] NGC 7243 lies at a distance of approximately 2,864 light-years (878.0 pc).[2]

This cluster has a Trumpler class of II 2m, indicating moderate dispersion, average brightness, and average richness of stars. A 2003 study found a combined mass in the range of 348 to 522 M, with 211 candidate members identified down to magnitude 15.5. The main sequence turnoff for its membership yields an age estimate of (2.5±0.5)×108 years. The brightest component is magnitude 8.43, and the earliest spectral type is B5 III.[5]

In 2016, the results of multiple observing campaigns over the span of a decade found 37 eclipsing binary star systems in the cluster, as well as 26 pulsating variables. One exoplanet transit candidate was identified, J221550.6+495611.[9]

Map showing location of NGC 7243

References

  1. 1.0 1.1 Gaia Collaboration (June 2023). "Gaia Data Release 3. Mapping the asymmetric disc of the Milky Way". Astronomy & Astrophysics 674: id. A37. doi:10.1051/0004-6361/202243797. Bibcode2023A&A...674A..37G. 
  2. 2.0 2.1 Poggio, E. et al. (2021). "Galactic spiral structure revealed by Gaia EDR3". Astronomy and Astrophysics 651: A104. doi:10.1051/0004-6361/202140687. Bibcode2021A&A...651A.104P. 
  3. 3.0 3.1 O'Meara, Stephen James (2007). Herschel 400 Observing Guide. Cambridge University Press. p. 273. ISBN 9780521858939. https://books.google.com/books?id=Nyh9fAC_tpIC&pg=PA273. 
  4. Cantat-Gaudin, T.; Anders, F. (January 2020). "Clusters and mirages: cataloguing stellar aggregates in the Milky Way". Astronomy & Astrophysics 633: 22. doi:10.1051/0004-6361/201936691. A99. Bibcode2020A&A...633A..99C. 
  5. 5.0 5.1 5.2 Jilinski, E. G. (April 2003). "Memberships and CM diagrams of the open cluster NGC 7243". Astronomy and Astrophysics 401: 531–541. doi:10.1051/0004-6361:20030112. Bibcode2003A&A...401..531J. 
  6. "NGC 7243". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=NGC+7243. 
  7. Seligman, Courtney. "NGC 7243". Celestial Atlas: NGC Objects: NGC 7200 - 7249. https://cseligman.com/text/atlas/ngc72.htm#7243. 
  8. "NGC 7243". eSky. http://www.glyphweb.com/esky/clusters/ngc7243.html. 
  9. Garai, Z. (March 2016). "Search for transiting exoplanets and variable stars in the open cluster NGC 7243". Astronomische Nachrichten 337 (3): 261–285. doi:10.1002/asna.201512310. Bibcode2016AN....337..261G. 

Further reading

  • Braun, W. G. (1999). "Is NGC 7243 an open star cluster?". Abstracts of Contributed Talks and Posters presented at the Annual Scientific Meeting of the Astronomische Gesellschaft, in Goettingen, 20-25 September 1999. 15. Bibcode1999AGM....15..P60B. 
  • Maitzen, H. M.; Pavlovski, K. (December 1987). "Photoelectric search for CP2-stars in open clusters. XII. Alpha Persei, Praesepe and NGC 7243". Astronomy and Astrophysics, Supplement Series 71: 441–448. Bibcode1987A&AS...71..441M. 
  • Hill, G.; Barnes, J. V. (March 1971). "A spectroscopic and photometric investigation of NGC 7243". Astronomical Journal 76: 110–116. doi:10.1086/111094. Bibcode1971AJ.....76..110H. 

Coordinates: Sky map 22h 15m 08.6s, +49° 53′ 51″