Astronomy:Delta Lyrae cluster
| Delta Lyrae cluster | |
|---|---|
 Lyra with the δ Lyrae pair and surrounding cluster stars left of centre | |
| Observation data (J2000 epoch) | |
| Constellation | Lyra |
| Right ascension | 18h 53m 30.(0)s[1] |
| Declination | +36° 55′ 0(0)″[1] |
| Distance | 1,220 ly (373 pc)[2] |
| Apparent magnitude (V) | 3.8[3] |
| Apparent dimensions (V) | 20′[3] |
| Physical characteristics | |
| Mass | 589[4] M☉ |
| Estimated age | 49 Myr[5] |
| Other designations | Stephenson 1[6] |
Delta Lyrae cluster or Stephenson 1[6] is a sparse open cluster of stars located about 1,220[2] light years away in the northern constellation of Lyra. Centered on the bright star Delta2 Lyrae for which it is named[3] but not a member like Delta1 Lyrae is with 70% certainty.[6]
This cluster was first suspected in 1959 by American astronomer Charles B. Stephenson, then was later concluded not to exist by German astronomer Werner Bronkalla in 1963. However, subsequent photometric observations at the Palomar and Mount Wilson observatories led American astronomer Olin J. Eggen to demonstrate that there was an actual cluster, at least for the observed stars down to absolute magnitude +5.5. Eggen's study found at least 33 members.[7]
The cluster has a visual magnitude of 3.8 and spans an angular diameter of 20 arc minutes.[3] The tidal radius of the cluster is 38 ly (11.5 pc) and it has an estimated combined mass of 589 times the mass of the Sun.[4] Based upon its estimated age and motion through space, it may be associated with the Gould Belt.[5] It includes an Algol variable star, BD+36° 3317, discovered in 2007 from Spain: this is a spectroscopic binary star system that undergoes regular eclipses because the orbital plane is nearly aligned with the line of sight to the Earth.[2]
An exoplanet has been found orbiting the star Kepler-1627 in this cluster.[8]
See also
References
- ↑ 1.0 1.1 Wu, Zhen-Yu et al. (November 2009), "The orbits of open clusters in the Galaxy", Monthly Notices of the Royal Astronomical Society 399 (4): 2146–2164, doi:10.1111/j.1365-2966.2009.15416.x, Bibcode: 2009MNRAS.399.2146W.
- ↑ 2.0 2.1 2.2 Özdarcan, O. et al. (July 2012), "BD+36 3317: An algol type eclipsing binary in Delta Lyrae cluster", New Astronomy 17 (5): 483–487, doi:10.1016/j.newast.2011.12.002, Bibcode: 2012NewA...17..483O.
- ↑ 3.0 3.1 3.2 3.3 Crossen, Craig; Rhemann, Gerald (2012), Sky Vistas: Astronomy for Binoculars and Richest-Field Telescopes, Springer Science & Business Media, ISBN 978-3709106266, https://books.google.com/books?id=3vELBwAAQBAJ&pg=PA61, retrieved 2015-11-10.
- ↑ 4.0 4.1 Piskunov, A. E. et al. (January 2008), "Tidal radii and masses of open clusters", Astronomy and Astrophysics 477 (1): 165–172, doi:10.1051/0004-6361:20078525, Bibcode: 2008A&A...477..165P.
- ↑ 5.0 5.1 Piskunov, A. E. et al. (January 2006), "Revisiting the population of Galactic open clusters", Astronomy and Astrophysics 445 (2): 545–565, doi:10.1051/0004-6361:20053764, Bibcode: 2006A&A...445..545P.
- ↑ 6.0 6.1 6.2 "NAME del Lyr Cluster". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=NAME+del+Lyr+Cluster.
- ↑ Eggen, O. J. (April 1968), "Photometric evidence for the existence of a delta Lyrae cluster", Astrophysical Journal 152: 77, doi:10.1086/149525, Bibcode: 1968ApJ...152...77E.
- ↑ Bouma, L. G. et al. (March 2022). "A 38 Million Year Old Neptune-sized Planet in the Kepler Field". The Astronomical Journal 163 (3): 121. doi:10.3847/1538-3881/ac4966. Bibcode: 2022AJ....163..121B.
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