LO Pegasi: Difference between revisions
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| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Pegasus |
| Right ascension | 21h 31m 01.714s[1] |
| Declination | 23° 20′ 07.37″[1] |
| Apparent magnitude (V) | 9.23[2] (9.04 to 9.27)[3] |
| Characteristics | |
| Spectral type | K3Vke[4] |
| B−V color index | 1.050±0.015[2] |
| Variable type | BY Dra[3] |
| Astrometry | |
| Radial velocity (Rv) | −23.36±1.75[5] km/s |
| Proper motion (μ) | RA: 134.654 mas/yr[1] Dec.: −144.889 mas/yr[1] |
| Parallax (π) | 41.2912 ± 0.0169 mas[1] |
| Distance | 78.99 ± 0.03 ly (24.218 ± 0.010 pc) |
| Absolute magnitude (MV) | 7.26[2] |
| Details[6] | |
| Mass | 0.66±0.02 M☉ |
| Radius | 0.72±0.10 R☉ |
| Luminosity | 0.25±0.02 L☉ |
| Surface gravity (log g) | 4.5±0.5 cgs |
| Temperature | 4,750±250 K |
| Rotation | 0.4236 d[7] |
| Rotational velocity (v sin i) | 48.2±2.5[8] km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
LO Pegasi is a single[10] star in the northern constellation of Pegasus that has been the subject of numerous scientific studies.[11] LP Peg is the variable star designation. It is too faint to be viewed with the naked eye, having an apparent visual magnitude that ranges from 9.04 down to 9.27.[3] Based on parallax measurements, LP Peg is located at a distance of 79 light years from the Sun. It is a member of the young AD Doradus group of co-moving stars,[10] and is drifting closer with a radial velocity of −23 km/s.[5]
This is a K-type main-sequence star with a stellar classification of K3Vke,[4] where the 'k' suffix indicates interstellar absorption lines and 'e' means there are emission lines in the spectrum. It became of interest to astronomers when significant X-ray emission was detected from this star in 1994. R. D. Jeffries and associates reported flare activity based on a rotationally-broadened Hydrogen α emission line and found the star varied in brightness.[12]
LO Peg is an ultra-rapid rotator, completing a full rotation every 10.15 hours.[13] It is classified as a BY Draconis variable that it is magnetically active and has star spots. The combination of non-uniform surface brightness and rotation makes it appear to vary in luminosity.[3] Up to 25.7% of the surface is covered in spots. Long term changes in periodicity suggest activity cycles, similar to the solar cycle, with periods of approximately 2.2 and 6 years.[14] The element lithium has been detected in its atmosphere, whose abundance, in combination with the star's rapid rotation, indicates this is a young star with an age of no more than a few hundred million years.[12]
References
- ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c d Samus', N. N; et al. (2017), "General catalogue of variable stars", Astronomy Reports, GCVS 5.1, 61 (1): 80, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
- ^ a b Gray, R. O.; et al. (2003), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I", The Astronomical Journal, 126 (4): 2048, arXiv:astro-ph/0308182, Bibcode:2003AJ....126.2048G, doi:10.1086/378365, S2CID 119417105.
- ^ a b 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.
- ^ Pandey, J. C.; et al. (September 2005), "Optical and X-Ray Studies of Chromospherically Active Stars: FR Cancri, HD 95559, and LO Pegasi", The Astronomical Journal, 130 (3): 1231–1246, arXiv:astro-ph/0506010, Bibcode:2005AJ....130.1231P, doi:10.1086/432539.
- ^ Strassmeier, Klaus G. (September 2009), "Starspots", The Astronomy and Astrophysics Review, 17 (3): 251–308, Bibcode:2009A&ARv..17..251S, doi:10.1007/s00159-009-0020-6.
- ^ Frasca, A.; et al. (May 1, 2018), "A spectroscopic survey of the youngest field stars in the solar neighborhood . II. The optically faint sample", Astronomy and Astrophysics, 612: A96, arXiv:1801.00671, Bibcode:2018A&A...612A..96F, doi:10.1051/0004-6361/201732028, ISSN 0004-6361, S2CID 119537437.
- ^ "LO Peg", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2022-03-28.
- ^ a b Azulay, R.; et al. (June 2017), "Young, active radio stars in the AB Doradus moving group", Astronomy & Astrophysics, 602: 15, arXiv:1703.08877, Bibcode:2017A&A...602A..57A, doi:10.1051/0004-6361/201629899, A57.
- ^ Savanov, I.; et al. (May 2019), "Activity of rapidly rotating dwarf LO Peg an [sic] giant FK Com", Contributions of the Astronomical Observatory Skalnaté Pleso, 49 (2): 415–419, Bibcode:2019CoSka..49..415S.
- ^ a b Jeffries, R. D.; et al. (September 1994), "BD +22 4409 : a rapidly rotating, low-mass member of the Local Association", Monthly Notices of the Royal Astronomical Society, 270: 153–172, Bibcode:1994MNRAS.270..153J, doi:10.1093/mnras/270.1.153.
- ^ Lalitha, S.; et al. (February 10, 2017), "Structure and variability in the corona of the ultrafast rotator LO Pegasi", Astronomy & Astrophysics, 602: 11, arXiv:1702.03158, Bibcode:2017A&A...602A..26L, doi:10.1051/0004-6361/201629482, A26.
- ^ Karmakar, Subhajeet; et al. (July 2016), "LO Peg: surface differential rotation, flares, and spot-topographic evolution", Monthly Notices of the Royal Astronomical Society, 459 (3): 3112–3129, arXiv:1608.06522, Bibcode:2016MNRAS.459.3112K, doi:10.1093/mnras/stw855.
Further reading
- Savanov, I. S.; et al. (July 2018), "Photometric Observations of LO Peg in 2017", Astrophysical Bulletin, 73 (3): 344–350, Bibcode:2018AstBu..73..344S, doi:10.1134/S1990341318030082.
- Savanov, I. S.; et al. (September 2016), "Photometric Observations of LO Peg in 2014-2015", Acta Astronomica, 66 (3): 381–390, Bibcode:2016AcA....66..381S.
- Pandey, S. B.; et al. (December 2014), "Long-term spot topography and multi-band flare analysis of active ultra-fast rotator LO Peg", Proceedings of Swift: 10 Years of Discovery (SWIFT 10), held 2-5 December 2014 at La Sapienza University, Rome, Italy, Bibcode:2014styd.confE.155P.
- Pandey, J. C.; et al. (August 2011), "Optical polarimetry and photometry of young sun-like star LO Peg", The Physics of Sun and Star Spots, Proceedings of the International Astronomical Union, IAU Symposium, vol. 273, pp. 455–459, Bibcode:2011IAUS..273..455P, doi:10.1017/S1743921311015766.
- Taš, G. (January 2011), "Long-term photometry of the ultra-fast rotator LO Peg", Astronomische Nachrichten, 332 (1): 57–64, Bibcode:2011AN....332...57T, doi:10.1002/asna.201011487.
- Pandey, J. C.; et al. (June 2009), "LO Pegasi: an investigation of multiband optical polarization", Monthly Notices of the Royal Astronomical Society, 396 (2): 1004–1011, arXiv:0903.2558, Bibcode:2009MNRAS.396.1004P, doi:10.1111/j.1365-2966.2009.14762.x.
- Barnes, J. R.; et al. (February 2005), "LO Peg in 1998: star-spot patterns and differential rotation", Monthly Notices of the Royal Astronomical Society, 356 (4): 1501–1508, arXiv:astro-ph/0410596, Bibcode:2005MNRAS.356.1501B, doi:10.1111/j.1365-2966.2004.08588.x.
- Harmon, R. O.; Saranathan, V. (December 2004), "Spot topography of BD+22o 4409 (LO Peg) using Matrix Light-curve Inversion", Bulletin of the American Astronomical Society, 36: 1361, Bibcode:2004AAS...205.1410H.
- Piluso, N.; et al. (June 2008), "Doppler imaging of the young late-type star LO Pegasi (BD+22°4409) in 2003 September", Monthly Notices of the Royal Astronomical Society, 387 (1): 237–246, arXiv:0802.3957, Bibcode:2008MNRAS.387..237P, doi:10.1111/j.1365-2966.2008.13153.x.
- Csorvási, R. (September 2006), Forgács-Dajka, E. (ed.), "Photometry of LO Pegasi in B, V, R colors", Proceedings of the 4th Workshop of Young Researchers in Astronomy & Astrophysics; Budapest, Hungary, 11-13 January, 2006, vol. 17, Astronomy Department of the Eötvös University (PADEU), p. 95, Bibcode:2006PADEU..17...95C.
- Pandey, J. C.; et al. (September 2005), "Optical and X-Ray Studies of Chromospherically Active Stars: FR Cancri, HD 95559, and LO Pegasi", The Astronomical Journal, 130 (3): 1231–1246, arXiv:astro-ph/0506010, Bibcode:2005AJ....130.1231P, doi:10.1086/432539.
- Barnes, J. R.; et al. (February 2005), "LO Peg in 1998: star-spot patterns and differential rotation", Monthly Notices of the Royal Astronomical Society, 356 (4): 1501–1508, arXiv:astro-ph/0410596, Bibcode:2005MNRAS.356.1501B, doi:10.1111/j.1365-2966.2004.08588.x.
- Harmon, R. O.; Saranathan, V. (December 2004), "Spot topography of BD+22o 4409 (LO Peg) using Matrix Light-curve Inversion", Bulletin of the American Astronomical Society, 36: 1361, Bibcode:2004AAS...205.1410H.
- Dal, H. A.; Tas, G. (March 2003), "New Photoelectric Photometry of the Young Star LO Pegasi", Information Bulletin on Variable Stars, 5390 (1), Bibcode:2003IBVS.5390....1D.
- Lister, T. A.; et al. (August 1999), "Doppler imaging of BD+22° 4409 (LO Peg) using least-squares deconvolution", Monthly Notices of the Royal Astronomical Society, 307 (3): 685–694, Bibcode:1999MNRAS.307..685L, doi:10.1046/j.1365-8711.1999.02662.x.
- Eibe, M. T.; et al. (January 1999), "Evidence for large-scale, global mass inflow and flaring on the late-type fast rotator BD+22 deg 4409", Astronomy and Astrophysics, 341: 527–538, Bibcode:1999A&A...341..527E.
- Robb, R. M.; Cardinal, R. D. (August 1995), "Optical Observations of the Active Star RE J2131+233", Information Bulletin on Variable Stars, 4221 (1), Bibcode:1995IBVS.4221....1R.
