Pi1 Ursae Majoris

Pi1 Ursae Majoris
Diagram showing star positions and boundaries of the Centaurus constellation and its surroundings
Location of π¹ Ursae Majoris (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Ursa Major
Right ascension 08h 39m 11.70440s[1]
Declination +65° 01′ 15.2667″[1]
Apparent magnitude (V) 5.63
Characteristics
Spectral type G1.5Vb[2]
U−B color index +0.07[3]
B−V color index +0.62[3]
Variable type BY Draconis
Astrometry
Radial velocity (Rv)–13.88 ± 0.47[4] km/s
Proper motion (μ) RA: -27.44 ± 0.31[1] mas/yr
Dec.: +88.13 ± 0.26[1] mas/yr
Parallax (π)69.66 ± 0.37[1] mas
Distance46.8 ± 0.2 ly
(14.36 ± 0.08 pc)
Absolute magnitude (MV)4.86[5]
Details
Mass0.90[6] M☉
Luminosity0.97[7] L☉
Surface gravity (log g)4.48[8] cgs
Temperature5,884 ± 6.8[9] K
Metallicity [Fe/H]–0.04[8] dex
Rotation5 days[10]
Rotational velocity (v sin i)14.27[4] km/s
Age200[11] Myr
Other designations
π¹ Ursae Majoris, π¹ UMa, Pi1 UMa, 3 Ursae Majoris, BD +65°643, GC 11817, HD 72905, HIP 42438, HR 3391, PPM 16705, SAO 14609.
Database references
SIMBADdata

Pi1 Ursae Majoris (Pi1 UMa, π¹ Ursae Majoris, π¹ UMa) is a yellow G-type main sequence dwarf with a mean apparent magnitude of +5.63. It is approximately 46.8 light years from Earth,[1] and is a relatively young star with an age of about 200 million years.[11] It is classified as a BY Draconis type variable star and its brightness varies by 0.08 magnitudes. In 1986, it became the first solar-type star to have the emission from an X-ray flare observed.[12] Based upon its space velocity components, this star is a member of the Ursa Major moving group of stars that share a common motion through space.[7][10]

An excess of infrared radiation has been detected from this system, which suggests the presence of a debris disk. The best fit to the data indicates that there is a ring of fine debris out to a radius of about 0.4 AU, consisting of 0.25 μm grains of amorphous silicates or crystalline forsterite. There may also be a wider ring of larger (10 μm) grains out to a distance of 16 AU.[13]

References

  1. 1 2 3 4 5 6 van Leeuwen, Floor (2007). Hipparcos, the new Reduction of the Raw data. Astrophysics and Space Science Library. 350. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. ISBN 978-1-4020-6341-1. Note: see VizieR catalogue I/311.
  2. ↑ Montes, D.; et al. (November 2001), "Late-type members of young stellar kinematic groups - I. Single stars", Monthly Notices of the Royal Astronomical Society, 328 (1): 45–63, arXiv:astro-ph/0106537, Bibcode:2001MNRAS.328...45M, doi:10.1046/j.1365-8711.2001.04781.x
  3. 1 2 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J
  4. 1 2 White, Russel J.; Gabor, Jared M.; Hillenbrand, Lynne A. (June 2007), "High-Dispersion Optical Spectra of Nearby Stars Younger Than the Sun", The Astronomical Journal, 133 (6): 2524–2536, arXiv:0706.0542, Bibcode:2007AJ....133.2524W, doi:10.1086/514336
  5. ↑ Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191.
  6. ↑ Shaya, Ed J.; Olling, Rob P. (January 2011), "Very Wide Binaries and Other Comoving Stellar Companions: A Bayesian Analysis of the Hipparcos Catalogue", The Astrophysical Journal Supplement, 192 (1): 2, arXiv:1007.0425, Bibcode:2011ApJS..192....2S, doi:10.1088/0067-0049/192/1/2
  7. 1 2 Gaidos, E. J.; Henry, G. W.; Henry, S. M. (August 2000), "Spectroscopy and Photometry of Nearby Young Solar Analogs", The Astronomical Journal, 120 (2): 1006–1013, Bibcode:2000AJ....120.1006G, CiteSeerX 10.1.1.43.4478, doi:10.1086/301488
  8. 1 2 Cenarro, A. J.; et al. (January 2007), "Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters", Monthly Notices of the Royal Astronomical Society, 374 (2): 664–690, arXiv:astro-ph/0611618, Bibcode:2007MNRAS.374..664C, doi:10.1111/j.1365-2966.2006.11196.x
  9. ↑ Kovtyukh, V. V.; et al. (2003), "High precision effective temperatures for 181 F-K dwarfs from line-depth ratios", Astronomy and Astrophysics, 411 (3): 559–564, arXiv:astro-ph/0308429, Bibcode:2003A&A...411..559K, doi:10.1051/0004-6361:20031378
  10. 1 2 Maldonado, J.; et al. (October 2010), "A spectroscopy study of nearby late-type stars, possible members of stellar kinematic groups", Astronomy and Astrophysics, 521: A12, arXiv:1007.1132, Bibcode:2010A&A...521A..12M, doi:10.1051/0004-6361/201014948
  11. 1 2 Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal, 687 (2): 1264–1293, arXiv:0807.1686, Bibcode:2008ApJ...687.1264M, doi:10.1086/591785
  12. ↑ Landini, M.; et al. (March 1986), "EXOSAT detection of an X-ray flare from the solar type star Pi-prime UMa", Astronomy and Astrophysics, 157 (2): 217–222, Bibcode:1986A&A...157..217L
  13. ↑ Beichman, C. A.; et al. (2006), "IRS Spectra of Solar-Type Stars: A Search for Asteroid Belt Analogs", The Astrophysical Journal, 639 (2): 1166–1176, arXiv:astro-ph/0601467, Bibcode:2006ApJ...639.1166B, doi:10.1086/499424
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.