Astronomy:Pi2 Octantis
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Short description: Star in the constellation Octans
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| Observation data Epoch J2000.0 Equinox (celestial coordinates) | |
|---|---|
| Constellation | Octans |
| Right ascension | 15h 04m 46.9232s[1] |
| Declination | −83° 02′ 17.920″[1] |
| Apparent magnitude (V) | 5.64 ± 0.01[2] |
| Characteristics | |
| Spectral type | G8 Ib[3] |
| U−B color index | +1.15[4] |
| B−V color index | +1.3[4] |
| Astrometry | |
| Radial velocity (Rv) | −13.8 ± 0.3[5] km/s |
| Proper motion (μ) | RA: −8.312[1] mas/yr Dec.: −17.597[1] mas/yr |
| Parallax (π) | 2.0741 ± 0.0429[1] mas |
| Distance | 1,570 ± 30 ly (482 ± 10 pc) |
| Absolute magnitude (MV) | −3.19[6] |
| Details | |
| Mass | 7 ± 1[7] M☉ |
| Radius | 69.02+1.61 −1.53[8] R☉ |
| Luminosity | 2,709[9] L☉ |
| Temperature | 4,588[9] K |
| Rotational velocity (v sin i) | 5.7 ± 1.8[10] km/s |
| Age | 43 ± 3[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Pi2 Octantis, Latinized from π2 Octantis, is a solitary[11] star situated in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.64, allowing it to be faintly visible to the naked eye under ideal conditions. Located 1,570 light years away,[1] the star is approaching the Sun with a heliocentric radial velocity of −13.8 km/s.[5]
This object is an ageing late G-type supergiant that has 7 times the mass of the Sun[7] and 69.02 times the radius of the Sun.[8] It radiates at 2,709 solar luminosity from its enlarged photosphere at an effective temperature of 4,588 K,[9] giving it an orange-yellow glow. Despite its advanced state, Pi2 Octantis is still a young star at an age of 43 million years.[7] It spins modestly with a projected rotational velocity of 5.7 km/s.[10]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P. et al. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. ISSN 0004-6361. Bibcode: 2000A&A...355L..27H.
- ↑ Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations -90_ to -53_ƒ0.. Bibcode: 1975mcts.book.....H.
- ↑ 4.0 4.1 Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1 January 1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory 4: 99–110. Bibcode: 1966CoLPL...4...99J.
- ↑ 5.0 5.1 Gontcharov, G. A. (November 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. ISSN 1063-7737. Bibcode: 2006AstL...32..759G.
- ↑ Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation" (in en). Astronomy Letters 38 (5): 331–346. doi:10.1134/S1063773712050015. ISSN 1063-7737. Bibcode: 2012AstL...38..331A.
- ↑ 7.0 7.1 7.2 7.3 Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (1 January 2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun: Catalogue of young runaway stars". Monthly Notices of the Royal Astronomical Society 410 (1): 190–200. doi:10.1111/j.1365-2966.2010.17434.x. ISSN 0035-8711. Bibcode: 2011MNRAS.410..190T.
- ↑ 8.0 8.1 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.
- ↑ 9.0 9.1 9.2 McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (21 November 2012). "Fundamental parameters and infrared excesses of Hipparcos stars: Parameters and IR excesses from Hipparcos". Monthly Notices of the Royal Astronomical Society 427 (1): 343–357. doi:10.1111/j.1365-2966.2012.21873.x. ISSN 0035-8711. Bibcode: 2012MNRAS.427..343M.
- ↑ 10.0 10.1 De Medeiros, J. R.; Udry, S.; Burki, G.; Mayor, M. (November 2002). "A catalog of rotational and radial velocities for evolved stars: II. Ib supergiant stars". Astronomy & Astrophysics 395 (1): 97–98. doi:10.1051/0004-6361:20021214. ISSN 0004-6361. Bibcode: 2002A&A...395...97D.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E
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