Astronomy:HD 45184
HD 45184 is a star in the southern constellation of Canis Major. It is a yellow-hued star near the lower limit of visibility to the naked eye with an apparent visual magnitude of 6.37.[2] The star is located at a distance of 71.65 light years from the Sun based on parallax.[1] It is drifting closer with a radial velocity of −3.8 km/s.[1]
This object is an ordinary G-type main-sequence star with a stellar classification of G2Va,[3] and it is considered a solar twin.[5] The mass, size, and luminosity of the star are slightly higher than for the Sun, and it has a near solar metallicity – what astronomers term the abundance of elements with higher atomic numbers than helium. The star is around three billion years old and is spinning with a 20-day period.[6] It has a 5.14[9]-year magnetic activity cycle that has a lower amplitude than on the Sun.[7]
Planetary system
HD 45184 has a planet around 12 times as massive as Earth that takes 5.88 days to complete an orbit around its host star. This planet was detected using the radial velocity method.[10] It was later confirmed with Spitzer, whereupon a second candidate planet of similar mass was discovered orbiting with a 13.1 day period. The star was observed by Spitzer for a transit of the inner planet, but no event was detected.[11] Both Neptune-like planets have near circular orbits close to the host star.[7]
An infrared excess has been detected using the Multiband Imaging Photometer for Spitzer at a wavelength of 70 μm, making this a debris disk candidate.[12] Based upon blackbody models, it is orbiting 1.0 astronomical unit|AU from the host star with a mean temperature of 280 K. There may be an additional, 60 K debris disk orbiting at a distance of 22.89 AU.[13]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥12.19+1.06 −1.03 M⊕ |
0.0644+0.0020 −0.0021 |
5.8854±0.0003 | 0.07±0.05 | — | — |
| c | ≥8.81+1.09 −1.02 M⊕ |
0.1100+0.0034 −0.0036 |
13.1354+0.0026 −0.0025 |
0.07+0.07 −0.05 |
— | — |
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 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.
- ↑ 2.0 2.1 2.2 2.3 2.4 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series 71: 245. doi:10.1086/191373. Bibcode: 1989ApJS...71..245K.
- ↑ 4.0 4.1 4.2 Cutri, R. M. et al. (June 2003). 2MASS All Sky Catalog of point sources. NASA/IPAC. Bibcode: 2003tmc..book.....C.
- ↑ 5.0 5.1 Datson, Juliet et al. (March 2014). "Solar analogues and solar twins in the HARPS archive". Monthly Notices of the Royal Astronomical Society 439 (1): 1028–1037. doi:10.1093/mnras/stu026. Bibcode: 2014MNRAS.439.1028D.
- ↑ 6.0 6.1 6.2 6.3 6.4 Lorenzo-Oliveira, Diego et al. (May 2019). "Constraining the evolution of stellar rotation using solar twins". Monthly Notices of the Royal Astronomical Society: Letters 485 (1): L68–L72. doi:10.1093/mnrasl/slz034. Bibcode: 2019MNRAS.485L..68L.
- ↑ 7.0 7.1 7.2 7.3 7.4 Udry, S. et al. (February 2019). "The HARPS search for southern extra-solar planets. XLIV. Eight HARPS multi-planet systems hosting 20 super-Earth and Neptune-mass companions". Astronomy & Astrophysics 622: 29. doi:10.1051/0004-6361/201731173. A37. Bibcode: 2019A&A...622A..37U.
- ↑ "HD 45184". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+45184.
- ↑ Flores, M. et al. (May 2016). "Discovery of an activity cycle in the solar analog HD 45184. Exploring Balmer and metallic lines as activity proxy candidates". Astronomy & Astrophysics 589: 6. doi:10.1051/0004-6361/201628145. A135. Bibcode: 2016A&A...589A.135F.
- ↑ Mayor, M. (2011). The HARPS search for southern extra-solar planets XXXIV. Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets. Bibcode: 2011arXiv1109.2497M.
- ↑ Gillon, M. et al. (2017). "The Spitzer search for the transits of HARPS low-mass planets. II. Null results for 19 planets". Astronomy and Astrophysics 601: A117. doi:10.1051/0004-6361/201629270. Bibcode: 2017A&A...601A.117G.
- ↑ Koerner, D. W. et al. (February 2010). "New Debris Disk Candidates Around 49 Nearby Stars". The Astrophysical Journal Letters 710 (1): L26–L29. doi:10.1088/2041-8205/710/1/L26. Bibcode: 2010ApJ...710L..26K.
- ↑ Cotten, Tara H.; Song, Inseok (July 2016). "A Comprehensive Census of Nearby Infrared Excess Stars". The Astrophysical Journal Supplement Series 225 (1): 24. doi:10.3847/0067-0049/225/1/15. 15. Bibcode: 2016ApJS..225...15C.
 |  |
