Astronomy:HIP 11915
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cetus |
| Right ascension | 02h 33m 49.026s[1] |
| Declination | –19° 36′ 42.500″[1] |
| Apparent magnitude (V) | 8.58[2] |
| Characteristics | |
| Evolutionary stage | Main sequence |
| Spectral type | G5V[2] |
| Astrometry | |
| Radial velocity (Rv) | 14.45±0.14[3] km/s |
| Proper motion (μ) | RA: +223.559[1] mas/yr Dec.: +35.513[1] mas/yr |
| Parallax (π) | 18.6292 ± 0.0224[1] mas |
| Distance | 175.1 ± 0.2 ly (53.68 ± 0.06 pc) |
| Absolute magnitude (MV) | 4.83[4] |
| Details | |
| Mass | 0.991±0.003[5] M☉ |
| Radius | 0.974±0.001[1] R☉ |
| Luminosity | 1.0+0.13 −0.12[6] L☉ |
| Surface gravity (log g) | 4.47±0.008[5] cgs |
| Temperature | 5773±2[5] K |
| Metallicity [Fe/H] | −0.057±0.003[5] dex |
| Rotation | 27.4+1.2 −7.9[7] days |
| Rotational velocity (v sin i) | 0.99±0.15[8] km/s |
| Age | 3.87±0.39[5] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HIP 11915 is a G-type main-sequence star located about 175 light-years from Earth in the constellation Cetus. It is considered a solar twin, having very similar characteristics to those of the Sun, including mass, radius, temperature, metallicity and age.[lower-alpha 1] It has a planetary companion, HIP 11915 b, which has a mass and orbital distance similar to that of Jupiter.
With an apparent magnitude of 8.6, it cannot be seen with the unaided eye, but can be observed with binoculars.[11]
Stellar characteristics
HIP 11915 is a G-type main sequence star which has approximately the same mass, radius, luminosity, and temperature as the Sun. It is slightly younger than the Sun, at 3.87 billion years old.[5]
The star is slightly poor in metals, with a metallicity ([Fe/H]) of about −0.057, or about 88% of the amount of iron and other heavier metals found in the Sun. The elemental abundance pattern of this star shows clear odd-even effect, where elements with even atomic number are more abundant than odd-number elements. The odd-even effect of this star is slightly different than the Sun's, indicating a different supernova enrichment history.[5]
Planetary system
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥0.99±0.06 MJ | 4.8±0.1 | 3830±150 | 0.10±0.07 | — | — |
In 2015, a study reported the detection of a planet orbiting HIP 11915 in a low eccentricity, 3800-day period orbit. This discovery was made using the High Accuracy Radial Velocity Planet Searcher instrument mounted on the European Southern Observatory's 3.6-meter telescope, located at La Silla Observatory in Chile. With a minimum mass and orbit similar to that of Jupiter, it has been called a "Jupiter twin".[13] While the paper was unable to rule out stellar activity cycles, which could mimic planetary signals, it suggests the signal is more likely to be a planet.[12]
The radial velocity data also indicates that there is no gas giant in this system with an orbital period of less than 1000 days. This means that there could be one or more terrestrial planets in the inner parts of the system, and the possibility of a habitable Earth-like planet.[12]
Footnotes
- ↑ An exact solar twin would be a G2V star with a 5778 K temperature, an age of 4.6 billion years old, the same metallicity, and a 0.1% solar luminosity variation.[9][10]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 "HD 16008". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+16008.
- ↑ Soubiran, C.; Jasniewicz, G.; Chemin, L.; Zurbach, C.; Brouillet, N.; Panuzzo, P.; Sartoretti, P.; Katz, D. et al. (2018). "GaiaData Release 2. The catalogue of radial velocity standard stars.". Astronomy & Astrophysics (EDP Sciences) 616: A7. doi:10.1051/0004-6361/201832795. ISSN 0004-6361. Bibcode: 2018A&A...616A...7S. https://www.aanda.org/articles/aa/pdf/2018/08/aa32795-18.pdf. Retrieved 2025-07-30.
- ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Galarza, Jhon Yana et al. (29 January 2021). "Explosive nucleosynthesis of a metal-deficient star as the source of a distinct odd-even effect in the solar twin HIP 11915". Monthly Notices of the Royal Astronomical Society: Letters 502 (1): L104–L109. doi:10.1093/mnrasl/slab010. Bibcode: 2021MNRAS.502L.104Y.
- ↑ Sousa, S. G. et al. (September 2011). "Spectroscopic stellar parameters for 582 FGK stars in the HARPS volume-limited sample". Astronomy & Astrophysics 533: A141. doi:10.1051/0004-6361/201117699. Bibcode: 2011A&A...533A.141S.Vizier catalog entry
- ↑ Netto, Yuri; Lorenzo-Oliveira, Diego; Meléndez, Jorge; Yana Galarza, Jhon; Haywood, Raphaëlle D.; Spina, Lorenzo; dos Santos, Leonardo A. (2021-10-01). "Radial-velocity Precision of ESPRESSO Through the Analysis of the Solar Twin HIP 11915". The Astronomical Journal 162 (4): 160. doi:10.3847/1538-3881/ac1bb5. ISSN 0004-6256. Bibcode: 2021AJ....162..160N.
- ↑ dos Santos, Leonardo A.; Meléndez, Jorge; Nascimento, José-Dias do; Bedell, Megan; Ramírez, Iván; Bean, Jacob L.; Asplund, Martin; Spina, Lorenzo et al. (2016). "The Solar Twin Planet Search. IV. The Sun as a typical rotator and evidence for a new rotational braking law for Sun-like stars". Astronomy & Astrophysics (EDP Sciences) 592: A156. doi:10.1051/0004-6361/201628558. ISSN 0004-6361. Bibcode: 2016A&A...592A.156D. https://www.aanda.org/articles/aa/pdf/2016/08/aa28558-16.pdf. Retrieved 2025-07-30.
- ↑ "Solar Variability and Terrestrial Climate - NASA Science". 7 January 2013. https://science.nasa.gov/science-news/science-at-nasa/2013/08jan_sunclimate/.
- ↑ Williams, D.R. (2004). "Sun Fact Sheet". NASA. http://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html.
- ↑ "The star HIP 11915 in the constellation of Cetus". European Southern Observatory. 15 July 2015. http://www.eso.org/public/images/eso1529b/.
- ↑ 12.0 12.1 12.2 Bedell, M.; Meléndez, J.; Bean, J. L.; Ramírez, I.; Asplund, M.; Alves-Brito, A.; Casagrande, L.; Dreizler, S. et al. (2015-08-28). "The Solar Twin Planet Search". Astronomy & Astrophysics (EDP Sciences) 581: A34. doi:10.1051/0004-6361/201525748. ISSN 0004-6361. Bibcode: 2015A&A...581A..34B. http://www.eso.org/public/archives/releases/sciencepapers/eso1529/eso1529a.pdf. Retrieved 17 July 2015.
- ↑ "Jupiter Twin Discovered Around Solar Twin". European Southern Observatory. http://www.eso.org/public/news/eso1529/.
Coordinates: 
02h 33m 49.025s, −19° 36′ 42.5032″
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