U Lacertae

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U Lacertae
Lacerta constellation map.svg
Red circle.svg
Location of U Lacertae (circled)
Observation data
Epoch J2000       Equinox J2000
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  mas [5]
Distance 2,750 [6]   pc
Absolute magnitude  (MV)−5.6 [7]
Details
Mass 22 [7]   M☉
Radius 1,013 [8]   R☉
Luminosity 152,000 [8]   L☉
Temperature 3,535 [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
SIMBAD data

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 ULacLightCurve.png
A visual band light curve for U Lacertae, plotted from AAVSO data

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

Related Research Articles

Beta Cephei variables, also known as Beta Canis Majoris stars, are variable stars that exhibit small rapid variations in their brightness due to pulsations of the stars' surfaces, thought due to the unusual properties of iron at temperatures of 200,000 K in their interiors. These stars are usually hot blue-white stars of spectral class B and should not be confused with Cepheid variables, which are named after Delta Cephei and are luminous supergiant stars.

<span class="mw-page-title-main">Zeta Cephei</span> Star in the constellation Cepheus

Zeta Cephei is a star in the constellation of Cepheus. Zeta Cephei marks the left shoulder of Cepheus, the King of Joppa (Ethiopia). It is one of the fundamental stars of the MK spectral sequence, defined as type K1.5 Ib.

Pi2 Cygni, Latinized from π2 Cygni, is a triple star system in the northern constellation of Cygnus. It is visible to the naked eye about 2.5° east-northeast of the open cluster M39, having an apparent visual magnitude of 4.24. Based upon an annual parallax shift of 2.95 mas, it is located at a distance of roughly 1,100 light years from the Sun.

Nu Cephei is a class A2, fourth-magnitude supergiant star in the constellation Cepheus. It is a white pulsating α Cygni variable star located about 4,700 light-years from Earth.

<span class="mw-page-title-main">W Cephei</span> Variable star in the constellation Cepheus

W Cephei is a spectroscopic binary and variable star located in the constellation Cepheus. It is thought to be a member of the Cep OB1 stellar association at about 8,000 light years. The supergiant primary star is one of the largest known stars and as well as one of the most luminous red supergiants.

<span class="mw-page-title-main">V381 Cephei</span> Triple star system in the constellation Cepheus

V381 Cephei is a triple star system in the northern constellation of Cepheus. Its apparent magnitude is slightly variable between 5.5 and 5.7.

<span class="mw-page-title-main">1 Camelopardalis</span> Double star system in the constellation Camelopardalis

1 Camelopardalis is a double star system in the constellation Camelopardalis. Its combined apparent magnitude is 5.56 and it is approximately 800 parsecs (2,600 ly) away.

<span class="mw-page-title-main">5 Lacertae</span> Star in the constellation Lacerta

5 Lacertae is a spectroscopic binary in the constellation Lacerta. Its apparent magnitude is 4.36.

4 Lacertae is a single star in the northern constellation Lacerta, located about 2,600 light years away. This object visible to the naked eye as a white-hued star with an apparent visual magnitude of 4.55. It is moving closer to the Earth with a heliocentric radial velocity of −26 km/s. This star is a suspected member of the Lac OB1 association.

<span class="mw-page-title-main">10 Lacertae</span> Star in the constellation Lacerta

10 Lacertae is a star in the constellation Lacerta. With an apparent magnitude of 4.9, it is located around 700 parsecs (2,300 ly) distant in the small Lacerta OB1 association. It is a hot blue main-sequence star of spectral type O9V, a massive star that is currently fusing its core hydrogen. It is a suspected Beta Cephei variable star.

<span class="mw-page-title-main">V424 Lacertae</span> Star in the constellation Lacerta

V424 Lacertae is a red supergiant variable star in the constellation Lacerta. It is a member of the Lacerta OB1 stellar association.

<span class="mw-page-title-main">AX Circini</span> Binary star system in the constellation Circinus

AX Circini is a binary star system in the southern constellation of Circinus. It has a nominal magnitude of 5.91, which is bright enough to be visible to the naked eye. Based upon an annual parallax shift of 1.7 mas, it is located roughly 1,900 light-years from the Earth. The system is moving closer with a heliocentric radial velocity of −21 km/s.

<span class="mw-page-title-main">QZ Puppis</span> Star in the constellation Puppis

QZ Puppis is a class B2.5V star in the constellation Puppis. Its apparent magnitude is 4.5 and it is approximately 650 light years away based on parallax.

<span class="mw-page-title-main">KQ Puppis</span> Binary star in the constellation Puppis

KQ Puppis is a spectroscopic binary variable star in the constellation Puppis. A red supergiant star and a hot main sequence star orbit each other every 9,742 days. Its apparent magnitude varies between 4.82 and 5.17.

<span class="mw-page-title-main">V1073 Scorpii</span> Variable star in the constellation Scorpius

V1073 Scorpii is a variable star in the constellation Scorpius. It has a non-Greek Bayer designation of k Scorpii. The star has a blue-white hue and is visible to the naked eye with an apparent visual magnitude that fluctuates around +4.87. Parallax measurements yield a distance estimate of approximately 2,920 ly (896 pc) from the Sun, and it is drifting further away with a radial velocity of +7 km/s. It has an absolute magnitude of −6.8

<span class="mw-page-title-main">14 Lacertae</span> Binary star in the constellation Lacerta

14 Lacertae is a binary star system in the northern constellation Lacerta, located around 1,600 light years away. It has the variable star designation V360 Lacertae; 14 Lacertae is the Flamsteed designation. The system is barely visible to the naked eye in good seeing conditions, having a peak apparent visual magnitude of 5.91. It is moving closer to the Earth with a heliocentric radial velocity of −16 km/s.

<span class="mw-page-title-main">16 Lacertae</span> Triple star system in the constellation Lacerta

16 Lacertae is a triple star system in the northern constellation of Lacerta, located about 1,580 light years from the Sun. It has the variable star designation EN Lacertae; 16 Lacertae is the Flamsteed designation. This system is visible to the naked eye as a faint blue-white hued star with a maximum apparent visual magnitude of +5.587. It is moving closer to the Earth with a heliocentric radial velocity of –12 km/s.

<span class="mw-page-title-main">NGC 7419</span> Open cluster in the constellation Cepheus

NGC 7419 is an open cluster in the constellation Cepheus. It is heavily reddened and notable for containing five red supergiants, the highest number known in any cluster until the end of the 20th century, but probably no blue supergiants.

<span class="mw-page-title-main">12 Lacertae</span> Star in the constellation Lacerta

12 Lacertae is a wide binary star system in the northern constellation of Lacerta, located roughly 1,260 light years away from the Sun based on parallax. It is visible to the naked eye as a dim, blue-white hued point of light with a baseline apparent visual magnitude of 5.23. The system is drifting closer to the Earth with a mean heliocentric radial velocity of –12.5. It is a probable member of the I Lacertae OB association.

<span class="mw-page-title-main">DH Cephei</span> Binary star system in the constellation Cepheus

DH Cephei is a variable binary star system in the northern circumpolar constellation of Cepheus, positioned about two degrees to the east of the star system Delta Cephei. With an apparent visual magnitude of 8.61, it is too faint to be visible without a telescope. Based on parallax measurements, this system is located at a distance of approximately 9.6 kilolight-years from the Sun. At present it is moving closer to the Earth with a radial velocity of −33 km/s.

References

  1. 1 2 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752 . Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID   18759600.
  2. 1 2 3 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. 1 2 3 4 U Lac, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars Archived 2017-06-20 at the Wayback Machine , 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. arXiv: 1606.08053 . Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID   119231169.
  5. 1 2 3 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . 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. arXiv: 1501.02749 . Bibcode:2015MNRAS.447.3909R. doi:10.1093/mnras/stu2725. S2CID   118515353.
  7. 1 2 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. 1 2 3 Healy, Sarah; Horiuchu, Shunsaku; Colomer Moller, Marta; Milisavljevic, Dan; Tseng, Jeff; Bergin, Faith; Weil, Kathryn; Tanaka, Masaomi (17 July 2023). "Red Supergiant Candidates for Multimessenger Monitoring of the Next Galactic Supernova". arXiv: 2307.08785 [astro-ph.SR].
  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. arXiv: 1211.1153 . Bibcode:2012A&A...548A..97Z. doi:10.1051/0004-6361/201219186. S2CID   54789717.
  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.org. AAVSO. Retrieved 1 October 2021.
  13. ↑ Houk, N. (1963). "V1280 Sagttarii and the other long-period variables with secondary period". Astronomical Journal. 68: 253. Bibcode:1963AJ.....68..253H. doi:10.1086/108948.
  14. ↑ Adelman, Saul J. (2001). "Stars with the Largest Hipparcos Photometric Amplitudes". Baltic Astronomy. 10 (4): 589. Bibcode:2001BaltA..10..589A. doi: 10.1515/astro-2001-0403 . S2CID   116386247.
  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. Bibcode:2014ApJS..211...15Y. doi: 10.1088/0067-0049/211/1/15 . S2CID   73561291.
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