HD 1461

HD 1461

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Cetus[1]
Right ascension	00^h 18^m 41.8674^s[2]
Declination	−08° 03′ 10.8058″[2]
Apparent magnitude (V)	6.47[3]
Characteristics
Spectral type	G3VFe0.5[4]
Apparent magnitude (B)	7.14
Apparent magnitude (J)	5.329
Apparent magnitude (H)	5.041
Apparent magnitude (K)	4.897
U−B color index	0.29
B−V color index	0.68
V−R color index	0.35
R−I color index	0.32
Variable type	None
Astrometry
Radial velocity (Rv)	−10.14±0.09[3] km/s
Proper motion (μ)	RA: 417.875±0.098[2] mas/yr Dec.: −143.768±0.054[2] mas/yr
Parallax (π)	42.6090 ± 0.0557 mas[2]
Distance	76.5 ± 0.1 ly (23.47 ± 0.03 pc)
Absolute magnitude (MV)	4.63±0.03[5]
Details
Mass	1.05±0.02[6] M☉
Radius	1.2441±0.0305[7] R☉
Luminosity	1.1893±0.0476[7] L☉
Surface gravity (log g)	4.39 cgs
Temperature	5,386±60[7] K
Metallicity [Fe/H]	0.18±0.01[6] dex
Rotational velocity (v sin i)	4.8[8] km/s
Age	2.0±1.1[6] Gyr
Other designations
32 G. Ceti[9], BD−08°38, GJ 16.1, HD 1461, HIP 1499, HR 72, SAO 128690, PPM 182101, LTT 149, NLTT 950, GCRV 50265, 2MASS J00184182-0803105[10]
Database references
SIMBAD	data
Exoplanet Archive	data
ARICNS	data

HD 1461 is a star in the equatorial constellation of Cetus, near the western constellation border with Aquarius. It has the Gould designation 32 G. Ceti,^[9] while HD 1461 is the Henry Draper Catalogue identifier. This object has a yellow hue and is a challenge to view with the naked eye, having an apparent visual magnitude of 6.47.^[3] The star is located at a distance of 76.5 light-years (23.5 parsecs) from the Sun based on parallax,^[2] but is drifting closer with a radial velocity of −10 km/s.^[3]

This object is a G-type main-sequence star with a stellar classification of G3VFe0.5,^[4] where the suffix notation indicates a mild overabundance of iron. It is roughly two^[6] billion years old and is spinning with a projected rotational velocity of 5 km/s.^[8] This is a solar-type star with 5% greater mass compared to the Sun and 1.24 times the Sun's radius. The star is radiating 1.19^[7] times the luminosity of the Sun from its photosphere at an effective temperature of 5,386 K.^[7]

Planetary system

On 14 December 2009, scientists announced the discovery at least one planet orbiting around HD 1461.^[11][12] The planet, a super-Earth with a 5.8-day orbit was designated HD 1461 b. The data also contained evidence for additional planets with orbital periods of around 400 and 5000 days but the star showed small variations with similar periods, casting doubt on the interpretation of these signals as being caused by orbiting planets.

In 2011, a paper was published on the arXiv pre-print server giving an orbital solution incorporating data from the HARPS spectrograph. This solution recovered the previously-known planet HD 1461 b, and an additional planet in a 13.5-day orbit.^[13] The 13.5-day planet HD 1461 c was confirmed in 2015.^[14]

Other than HD 1461 b, the designations for the planets are inconsistent: in the original paper, Rivera et al. designated the 400 and 5000-day candidates as "c" and "d" respectively, whereas the Mayor et al. (2011) pre-print uses the "c" designation for the 13.5-day planet and does not mention the 400-day or 5000-day planets at all.

HD 1461 b has a mass 6.44 times that of the Earth while HD 1461 c has a mass times 5.59 that of the Earth.^[14]

The HD 1461 planetary system^[14]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥6.44±0.61 M🜨	0.0634±0.0022	5.77152±0.00045	<0.131	—	—
c	≥5.59±0.73 M🜨	0.1117±0.0039	13.5052±0.0029	<0.228	—	—

See also

• List of extrasolar planets
• List of stars in Cetus

References

1. Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific. 99 (617): 695–699. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Vizier query form
2. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
3. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644
4. Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
5. Holmberg; et al. (2009). "HD 1461". Geneva-Copenhagen Survey of Solar neighbourhood III. Retrieved 2010-12-04.
6. M. Tsantaki1; S. G. Sousa1; V. Zh. Adibekyan1; N. C. Santos1; A. Mortier1; G. Israelian (April 2013). "Deriving precise parameters for cool solar-type stars Optimizing the iron line list?" (PDF): 4. {{cite journal}}: Cite journal requires |journal= (help)
7. von Braun, Kaspar; et al. (2014). "Stellar diameters and temperatures - V. 11 newly characterized exoplanet host stars". Monthly Notices of the Royal Astronomical Society. 438 (3): 2413–2425. arXiv:1312.1792. Bibcode:2014MNRAS.438.2413V. doi:10.1093/mnras/stt2360.
8. Luck, R. Earle (January 2017), "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants", The Astronomical Journal, 153 (1): 19, arXiv:1611.02897, Bibcode:2017AJ....153...21L, doi:10.3847/1538-3881/153/1/21, S2CID 119511744, 21.
9. Gould, B. (1879). "32G Ceti". Uranometria Argentina. Retrieved 2012-05-24.
10. "HD 1461". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-11-02.
11. Rivera, Eugenio J.; et al. (2010). "A Super-Earth Orbiting the Nearby Sun-like Star HD 1461". The Astrophysical Journal. 708 (2): 1492–1499. arXiv:0912.2566. Bibcode:2010ApJ...708.1492R. doi:10.1088/0004-637X/708/2/1492. S2CID 12840404.
12. Tim Stephens (2009-12-14). "New planet discoveries suggest low-mass planets are common around nearby stars". UCSC News. UC Santa Cruz. Archived from the original on 2009-12-23. Retrieved 2009-12-14.
13. Mayor; et al. (September 2011). "The HARPS search for southern extra-solar planets XXXIV. Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets". arXiv:1109.2497 [astro-ph.EP].
14. Díaz, R. F.; et al. (2016). "The HARPS search for southern extra-solar planets. XXXVIII. Bayesian re-analysis of three systems. New super-Earths, unconfirmed signals, and magnetic cycles". Astronomy and Astrophysics. 585. A134. arXiv:1510.06446. Bibcode:2016A&A...585A.134D. doi:10.1051/0004-6361/201526729. S2CID 118531921.

External links

• Aladin image^{[permanent dead link‍]} of HD 1461