| 词条 | Gliese 49 |
| 释义 |
Gliese 49 (GJ 49 / HIP 4872)[1] is a star in the constellation of Cassiopeia. Visually, it is located 106 arc minutes north of the bright star γ Cassiopeiae. With an apparent magnitude of 9.56,[1] it is not observable with the naked eye. It is located, based on the reduction of parallax data of Hipparcos (100.40 ± 1.52 Millisecond of arc), 32.5 light-years away from the Solar System. Gliese 49 is a red dwarf of spectral type M1.5V. Much dimmer than Sun, it has a total luminosity that is 5.0% that of the Sun;[2] it is, however, much brighter than other nearby red dwarfs such as Proxima Centauri or Wolf 359. It has an effective temperature of 3454 ± 50 K. Its mass is 57% that of the Sun and its radius is 2/3 that of the Sun. It rotates on its axis with a projected rotation speed of 2.5 km/s, which means that its rotation period does not exceed 13.4 days. It has a metallic content similar to that of the Sun, with its index of metallicity [M / H] = +0.03.[3] Although its age is not known exactly, it is less than 250 million years. Gliese 49 has a similar proper motion to the red dwarf flare star V388 Cassiopeiae. The visual separation between the two is 295 arcseconds, which implies that the real distance between them is over 2900 AU. Both stars are associated with the Hyades, as suggested by its young age and chromospheric activity levels.[4] Planetary systemOne known planet is known to orbit Gliese 49. Gliese 49 b is a super-Earth planet detected by the radial velocity method.[5][6] {{OrbitboxPlanet begin}}{{OrbitboxPlanet|exoplanet=b | mass_earth={{val|5.63|+0.67|−0.68}}|period={{val|13.8508|+0.0053|−0.0051}}|semimajor=0.0905 ± 0.0011|eccentricity={{val|0.363|+0.099|−0.096}}}}{{Orbitbox end}}References1. ^1 LHS 1179 -- High proper-motion Star (SIMBAD) {{Stars of Cassiopeia}}2. ^{{cite journal|author=Morales, J. C.; Ribas, I.; Jordi, C.|title=The effect of activity on stellar temperatures and radii|year=2008|journal=Astronomy and Astrophysics | volume=478|number=2|id=pp. 507-512|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2008A%26A...478..507M&db_key=AST&nosetcookie=1}} 3. ^{{cite journal|author=Houdebine, E. R.|title=Observation and modelling of main-sequence star chromospheres – XIV. Rotation of dM1 stars|year=2010|journal=Monthly Notices of the Royal Astronomical Society | volume=407|number=3|id=pp. 1657–1673|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2010MNRAS.407.1657H&db_key=AST&nosetcookie=1}} 4. ^{{cite journal|author=Makarov, V. V.; Zacharias, N.; Hennessy, G. S.|title=Common Proper Motion Companions to Nearby Stars: Ages and Evolution|year=2008|journal=The Astrophysical Journal | volume=687|number=1|id=pp. 566-578|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2008ApJ...687..566M&db_key=AST&nosetcookie=1}} 5. ^{{Cite journal |last=Perger |first=M. |last2=Scandariato |first2=G. |last3=Ribas |first3=I. |last4=Morales |first4=J. C. |last5=Affer |first5=L. |last6=Azzaro |first6=M. |last7=Amado |first7=P. J. |last8=Anglada-Escudé |first8=G. |last9=Baroch |first9=D. |date=2019-03-15 |title=Gliese 49: Activity evolution and detection of a super-Earth |url=http://arxiv.org/abs/1903.04808 |journal=Astronomy & Astrophysics |doi=10.1051/0004-6361/201935192 |issn=0004-6361}} 6. ^{{cite web |url=https://arxiv.org/pdf/1903.04808.pdf |title=Gliese 49: Activity evolution and detection of a super-Earth? A HADES and CARMENES collaboration |last= |first= |date=25 March 2019 |website= |archive-url= |archive-date= |dead-url= |access-date=}} 4 : Gliese and GJ objects|Red dwarfs|Cassiopeia (constellation)|Hipparcos objects |
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