Astronomy:Nu Phoenicis
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Phoenix |
| Right ascension | 01h 15m 11.12150s[1] |
| Declination | –45° 31′ 53.9954″[1] |
| Apparent magnitude (V) | 4.95[2] |
| Characteristics | |
| Spectral type | F9 V Fe+0.4[3] |
| U−B color index | +0.09[2] |
| B−V color index | +0.57[2] |
| Astrometry | |
| Radial velocity (Rv) | +11.82 ± 0.15[4] km/s |
| Proper motion (μ) | RA: 664.28[4] mas/yr Dec.: 179.06[4] mas/yr |
| Parallax (π) | 65.8894 ± 0.1803[4] mas |
| Distance | 49.5 ± 0.1 ly (15.18 ± 0.04 pc) |
| Absolute magnitude (MV) | 4.07[5] |
| Details[5] | |
| Mass | 1.17 M☉ |
| Radius | 1.26 ± 0.04 R☉ |
| Luminosity | 2.0 ± 0.1 L☉ |
| Surface gravity (log g) | 4.31 ± 0.10 cgs |
| Temperature | 6,066 ± 70 K |
| Metallicity [Fe/H] | +0.16 ± 0.06 dex |
| Rotational velocity (v sin i) | 3.7 ± 0.5 km/s |
| Age | 4.2[6] Gyr |
| Other designations | |
CD–46° 346, GCTP 257.00, Gl 55, HD 7570, HIP 5862, HR 370, LHS 1220, LTT 696, SAO 215428.[7] | |
| Database references | |
| SIMBAD | data |
Nu Phoenicis is a F-type main-sequence star in the southern constellation of Phoenix. It is visible to the naked eye with an apparent visual magnitude of 4.95.[2] This is a solar analogue, meaning its observed properties appear similar to the Sun, although it is somewhat more massive. At an estimated distance of around 49.5 light years,[4] this star is located relatively near the Sun.
Based on observations of excess infrared radiation from this star, it may possess a dust ring that extends outward several AU from an inner edge starting at 10 AU.[8]
Properties
This is an F-type main-sequence star with a spectral type of F9V Fe+0.4,[3] indicating it is similar to the Sun but somewhat hotter and more luminous. The notation 'Fe+0.4' indicates strong iron absorption lines; the star is indeed metal-rich, with an iron abundance 45% greater than the Sun's. Nu Phoenicis has an estimated mass of 1.17 times the solar mass and a radius of 1.26 times the solar radius. It is shining with about double the solar luminosity at an effective temperature of 6,070 K.[5]
Nu Phoenicis has a projected rotational velocity of 3.7 km/s,[5] and a low chromospheric activity index (log R′HK = −4.95).[9] These values indicate that the star is not particularly young and has an age of a few billion years; empirical calibrations estimate from the rotational velocity an age of 2.4 billion years, and from the activity index an age of 5.67 billion years.[9] Similarly, stellar evolution models estimate an age between 1 and 6 billion years, with a more probable value of 4.2 billion years.[6]
Nu Phoenicis has no known companions, and is considered to be a single star.[5] As a bright star similar to the Sun, it has been targeted in a number of studies searching for planets with the radial velocity method, but no detection has been made. High-precision observations with the HARPS spectrograph show that the radial velocity of the star has no significant variability, and is constant to 2.67 m/s, a value similar to the estimated jitter level of 2.48 m/s.[10] The star has also been included in the observations of the Anglo-Australian Planet Search, which did not find Jupiter-analogs with periods up to 6,000 days.[11]
Nu Phoenicis emits a significant amount of infrared excess, in comparison to the expected emission from the star's photosphere, indicating it has a circumstellar debris disk that is warmed by the star and emits thermal radiation.[8] The excess has been detected in long wavelengths, between 30[8] and 100 μm,[12] indicating relatively cold dust many astronomical units away from the star. Modeling the emission as a black body, the disk has an estimated temperature of 96 K and a radius of 12 AU, contributing to 0.00024% of the system's luminosity.[12]
See also
References
- ↑ 1.0 1.1 van Leeuwen, F. (November 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.
- ↑ 2.0 2.1 2.2 2.3 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD: 0, Bibcode: 1986EgUBV........0M.
- ↑ 3.0 3.1 Gray, R. O. et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal 132 (1): 161–170, doi:10.1086/504637, Bibcode: 2006AJ....132..161G.
- ↑ 4.0 4.1 4.2 4.3 4.4 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.
- ↑ 5.0 5.1 5.2 5.3 5.4 Fuhrmann, K.; Chini, R.; Kaderhandt, L.; Chen, Z. (2017). "Multiplicity among Solar-type Stars". The Astrophysical Journal 836 (1): 139. doi:10.3847/1538-4357/836/1/139. Bibcode: 2017ApJ...836..139F.
- ↑ 6.0 6.1 Casagrande, L. et al. (June 2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy and Astrophysics 530: A138, doi:10.1051/0004-6361/201016276, Bibcode: 2011A&A...530A.138C.
- ↑ "nu. Phe -- High proper-motion Star", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+7570, retrieved 2015-12-22.
- ↑ 8.0 8.1 8.2 Beichman, C. A.; Tanner, A.; Bryden, G.; Stapelfeldt, K. R. et al. (2006). "IRS Spectra of Solar-Type Stars: A Search for Asteroid Belt Analogs". Astrophysical Journal 639 (2): 1166–1176. doi:10.1086/499424. Bibcode: 2006ApJ...639.1166B.
- ↑ 9.0 9.1 Vican, Laura (June 2012), "Age Determination for 346 Nearby Stars in the Herschel DEBRIS Survey", The Astronomical Journal 143 (6): 135, doi:10.1088/0004-6256/143/6/135, Bibcode: 2012AJ....143..135V.
- ↑ Zechmeister, M. et al. (2013). "The planet search programme at the ESO CES and HARPS. IV. The search for Jupiter analogues around solar-like stars". Astronomy & Astrophysics 592: A78. doi:10.1051/0004-6361/201116551. Bibcode: 2013A&A...552A..78Z.
- ↑ Wittenmyer, Robert A.; Butler, R. P.; Tinney, C. G.; Horner, Jonathan; Carter, B. D.; Wright, D. J.; Jones, H. R. A.; Bailey, J. et al. (2016). "The Anglo-Australian Planet Search XXIV: The Frequency of Jupiter Analogs". The Astrophysical Journal 819 (1): 28. doi:10.3847/0004-637x/819/1/28. Bibcode: 2016ApJ...819...28W.
- ↑ 12.0 12.1 Montesinos, B. et al. (September 2016), "Incidence of debris discs around FGK stars in the solar neighbourhood", Astronomy & Astrophysics 593: 31, doi:10.1051/0004-6361/201628329, A51, Bibcode: 2016A&A...593A..51M.
External links
- "HD 7570 -- High proper-motion Star". Simbad. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+7570&submit=SIMBAD+search.
- "4C00106". ARICNS. http://www.ari.uni-heidelberg.de/aricns/cnspages/4c00106.htm.
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