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) | +14.1 ± 0.5[1] km/s |
| Proper motion (μ) | RA: 225.590±0.082[1] mas/yr Dec.: 35.400±0.090[1] mas/yr |
| Parallax (π) | 18.63 ± 0.29[1] mas |
| Distance | 175 ± 3 ly (53.7 ± 0.8 pc) |
| Absolute magnitude (MV) | 4.83[3] |
| Details | |
| Mass | 0.991±0.003[4] M☉ |
| Radius | ~1.01 R☉ |
| Luminosity | 1.0+0.13 −0.12[5] L☉ |
| Surface gravity (log g) | 4.47±0.008[4] cgs |
| Temperature | 5773±2[4] K |
| Metallicity [Fe/H] | −0.057±0.003[4] dex |
| Rotational velocity (v sin i) | 0.99 ± 0.15 km/s |
| Age | 3.87±0.39[4] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Extrasolar Planets Encyclopaedia | data |
HIP 11915 is a G-type main-sequence star located about 190 light-years from Earth in the constellation Cetus.[2] It is best known for its characteristics, which are very similar to those of the Sun, including the mass, radius, temperature, metallicity and age, which means that it is almost a solar twin, being just 500 million years younger than the Sun and with a lower metallicity.[lower-alpha 1] It is also known for its planetary companion, HIP 11915 b, which has a mass and orbital distance very similar to that of Jupiter, but probably with a slightly higher orbital eccentricity.
This star is entry number 11915 in the Hipparcos Catalogue. The star is located at 02:33:49.02495 right ascension, −19° 36' 42.5032" dec.[1][8] Too faint to be seen with the unaided eye, the star can be spotted with good binoculars.[8]
Stellar characteristics
HIP 11915 is a G-type main sequence star that is just about the same mass of and likely 101% the radius of the Sun. It has a temperature of 5760 K and is 4.16 billion years old,[2][9] nearly 500 million years younger than the Sun, which is about 4.6 billion years old[10] and has a temperature of 5778 K.[11]
The star is slightly poor in metals, with a metallicity ([Fe/H]) of about −0.059, or about 87% of the amount of iron and other heavier metals found in the Sun.[9] Given the similar properties of the Sun, HIP 11915's luminosity is likely close to the same as the Sun (give or take about 10% in uncertainty).
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 ± .01 | 3830.0 ± 150 | 0.1 ± 0.07 | — | ~1 RJ |
The system contains a gas giant, HIP 11915 b, with a mass and orbit very similar to that of Jupiter, located at approximately the same distance from its star. The discovery of HIP 11915 b is significant, because it is the first, and to date only, distant planetary system found that may be somewhat like the Solar System.[12] The radial velocity data also indicates that there is no large 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.
This new discovery was made at the La Silla Observatory in Chile , using the High Accuracy Radial Velocity Planet Searcher instrument mounted on the European Southern Observatory's 3.6-meter telescope.[13][14]
According to Jorge Meléndez, who led the University of São Paulo, Brazil team that discovered HIP 11915 b, "the quest for an Earth 2.0, and for a complete Solar System 2.0, is one of the most exciting endeavors in astronomy".[15]
Comparison to the Sun
This chart compares the properties of the Sun to HIP 11915.
| Identifier | J2000 Coordinates | Distance (ly) |
Stellar Class |
Mass (M☉) |
Radius (R☉) |
Temperature (K) |
Metallicity (dex) |
Age (Gyr) |
Notes | |
|---|---|---|---|---|---|---|---|---|---|---|
| Right ascension | Declination | |||||||||
| Sun | — | — | 0.00 | G2V | 1 | 1 | 5,778 | +0.00 | 4.6 | [7] |
| HIP 11915 [16] | 02h 33m 49.02s | −19° 36′ 42.5″ | 190 | G5V | 0.99 | 1.01 | 5,760 | −0.059 | 4.1 | [17] |
Footnotes
- ↑ An exact solar twin would be a G2V star with a 5778 K temperature, be 4.6 billion years old, with the correct metallicity and a 0.1% solar luminosity variation.[6][7]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 "HD 16008". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+16008.
- ↑ 2.0 2.1 2.2 2.3 2.4 "Planet HIP 11915". Extrasolar Planets Encyclopaedia. http://exoplanet.eu/catalog/hip_11915/.
- ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 4.0 4.1 4.2 4.3 4.4 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
- ↑ "Solar Variability and Terrestrial Climate - NASA Science". https://science.nasa.gov/science-news/science-at-nasa/2013/08jan_sunclimate/.
- ↑ 7.0 7.1 Williams, D.R. (2004). "Sun Fact Sheet". NASA. http://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html.
- ↑ 8.0 8.1 "The star HIP 11915 in the constellation of Cetus". European Southern Observatory. 15 July 2015. http://www.eso.org/public/images/eso1529b/.
- ↑ 9.0 9.1 Dos Santos, Leonardo A. (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 592: A156. doi:10.1051/0004-6361/201628558. Bibcode: 2016A&A...592A.156D.
- ↑ Fraser Cain (16 September 2008). "How Old is the Sun?". Universe Today. http://www.universetoday.com/18237/how-old-is-the-sun/.
- ↑ Fraser Cain (15 September 2008). "Temperature of the Sun". Universe Today. http://www.universetoday.com/18092/temperature-of-the-sun/.
- ↑ "Jupiter's twin spotted". IANS. business standard. July 16, 2015. http://www.business-standard.com/article/news-ians/jupiter-s-twin-spotted-115071600300_1.html.
- ↑ "HIP 11915b: Jupiter Twin Found Orbiting Sun-Like Star". Sci-News.com. Jul 15, 2015. http://www.sci-news.com/astronomy/science-hip11915b-jupiter-twin-sun-like-star-03021.html.
- ↑ Bora, Kukil (16 July 2015). "Jupiter Look-Alike Discovered Orbiting Sun-Like Star; Could There Be An Earth Twin?". ib times. http://www.ibtimes.com/jupiter-look-alike-discovered-orbiting-sun-star-could-there-be-earth-twin-2011228.
- ↑ "Jupiter Twin Discovered Around Solar Twin". European Southern Observatory. http://www.eso.org/public/news/eso1529/.
- ↑ HIP 11915 at SIMBAD - Ids - Bibliography - Image.
- ↑ M. Bedell; J. Meléndez; J. L. Bean; I. Ramírez; M. Asplund; A. Alves-Brito; L. Casagrande; S. Dreizler et al. (June 26, 2015). "The Solar Twin Planet Search II. A Jupiter twin around a solar twin". Astronomy & Astrophysics 581: A34. doi:10.1051/0004-6361/201525748. Bibcode: 2015A&A...581A..34B. http://www.eso.org/public/archives/releases/sciencepapers/eso1529/eso1529a.pdf. Retrieved 17 July 2015.
Coordinates: 
02h 33m 49.025s, −19° 36′ 42.5032″
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