Astronomy:U Lacertae

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Short description: Binary star in the constellation Lacerta
U Lacertae
Lacerta constellation map.svg
Red circle.svg
Location of U Lacertae (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Lacerta
Right ascension  22h 47m 43.42677s[1]
Declination 55° 09′ 30.3036″[1]
Apparent magnitude (V) 9.40[2]
Characteristics
Spectral type M4epIab + B[3]
U−B color index +1.46[2]
B−V color index +2.34[2]
Variable type SRc[3]
Astrometry
Radial velocity (Rv)−68[4] km/s
Proper motion (μ) RA: −3.207 [5] mas/yr
Dec.: −3.150 [5] mas/yr
Parallax (π)0.3519 ± 0.0708[5] mas
Distance2,750[6] pc
Absolute magnitude (MV)−5.6[7]
Details
Mass22[7] M☉
Radius785[8] R☉
Luminosity87,000 - 93,000[8] L☉
Temperature3,535±170[8] K
Other designations
U Lac, HIP 112545, PPM 411, GSC 03988-01641, IRC+50446, TYC 3988-1641-1, BD+54 2863, HD 215924, 2MASS J22474341+5509303, AAVSO 2243+54
Database references
SIMBADdata

U Lacertae is a spectroscopic binary star in the constellation Lacerta.

Despite being in the constellation of Lacerta, U Lacertae is considered to be a member of the Cepheus OB1 association.[9] It has been listed as a member of the open cluster ASCC 123.[10]

U Lacertae is a VV Cephei binary consisting of a red supergiant and a small hot companion. The companion has been identified from a high excitation component in the spectrum and from radial velocity variations, but the orbit is unknown.[11]

A visual band light curve for U Lacertae, plotted from AAVSO data[12]

U Lacertae is a variable star classified as a semiregular variable.[3] The periodicity is uncertain but a main period of 150 days and a long secondary period of 550 – 690 days have been suggested.[13] A study of Hipparcos satellite photometry found an amplitude of 0.77 magnitudes and found no periodicity.[14] The General Catalogue of Variable Stars lists an amplitude of 2.7 magnitudes.[3]

Water masers have been detected around U Lacertae, common in the extended atmospheres of very luminous cool stars.[15]

See also

References

  1. ↑ 1.0 1.1 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V. 
  2. ↑ 2.0 2.1 2.2 Ducati, J. R. (2002). "VizieR On-line Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues 2237. Bibcode: 2002yCat.2237....0D. 
  3. ↑ 3.0 3.1 3.2 3.3 U Lac, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars , Sternberg Astronomical Institute, Moscow, Russia. Accessed on line November 12, 2010.
  4. ↑ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode: 2006AstL...32..759G. 
  5. ↑ 5.0 5.1 5.2 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  6. ↑ Reiter, Megan; Marengo, Massimo; Hora, Joseph L.; Fazio, Giovanni G. (2015). "A Spitzer/IRAC characterization of Galactic AGB and RSG stars". Monthly Notices of the Royal Astronomical Society 447 (4): 3909. doi:10.1093/mnras/stu2725. Bibcode: 2015MNRAS.447.3909R. 
  7. ↑ 7.0 7.1 Stothers, R.; Leung, K. C. (1971). "Luminosities, masses and periodicities of massive red supergiants". Astronomy and Astrophysics 10: 290. Bibcode: 1971A&A....10..290S. 
  8. ↑ 8.0 8.1 8.2 Messineo, M.; Brown, A. G. A. (2019). "A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2". The Astronomical Journal 158 (1): 20. doi:10.3847/1538-3881/ab1cbd. Bibcode: 2019AJ....158...20M. 
  9. ↑ Garmany, C. D.; Stencel, R. E. (1992). "Galactic OB associations in the northern Milky Way Galaxy. I - Longitudes 55 deg to 150 deg". Astronomy and Astrophysics Supplement Series 94: 211. Bibcode: 1992A&AS...94..211G. 
  10. ↑ Zejda, M.; Paunzen, E.; Baumann, B.; Mikulášek, Z.; Liška, J. (2012). "Catalogue of variable stars in open cluster fields". Astronomy & Astrophysics 548: A97. doi:10.1051/0004-6361/201219186. Bibcode: 2012A&A...548A..97Z. 
  11. ↑ Burki, G.; Mayor, M. (1983). "Nineteen new spectroscopic binaries and the rate of binary stars among F-M supergiants". Astronomy and Astrophysics 124: 256. Bibcode: 1983A&A...124..256B. 
  12. ↑ "Download Data". AAVSO. https://www.aavso.org/data-download. 
  13. ↑ Houk, N. (1963). "V1280 Sagttarii and the other long-period variables with secondary period". Astronomical Journal 68: 253. doi:10.1086/108948. Bibcode: 1963AJ.....68..253H. 
  14. ↑ Adelman, Saul J. (2001). "Stars with the Largest Hipparcos Photometric Amplitudes". Baltic Astronomy 10 (4): 589. doi:10.1515/astro-2001-0403. Bibcode: 2001BaltA..10..589A. 
  15. ↑ Yoon, Dong-Hwan; Cho, Se-Hyung; Kim, Jaeheon; Yun, Young joo; Park, Yong-Sun (2014). "SiO and H2O Maser Survey toward Post-asymptotic Giant Branch and Asymptotic Giant Branch Stars". The Astrophysical Journal Supplement 211 (1): 15. doi:10.1088/0067-0049/211/1/15. Bibcode: 2014ApJS..211...15Y. 



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