Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Cetus [1] |
Right ascension | 00h 18m 41.8674s [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 | |
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]
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]
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 | — | — |
Tau Ceti, Latinized from τ Ceti, is a single star in the constellation Cetus that is spectrally similar to the Sun, although it has only about 78% of the Sun's mass. At a distance of just under 12 light-years from the Solar System, it is a relatively nearby star and the closest solitary G-class star. The star appears stable, with little stellar variation, and is metal-deficient relative to the Sun.
82 G. Eridani is a star 19.7 light-years away from Earth in the constellation Eridanus. It is a main-sequence star with a stellar classification of G6 V, and it hosts a system of at least three planets and a dust disk.
Gliese 65, also known as Luyten 726-8, is a binary star system that is one of Earth's nearest neighbors, at 8.8 light-years from Earth in the constellation Cetus. The two component stars are both flare stars with the variable star designations BL Ceti and UV Ceti.
79 Ceti, also known as HD 16141, is a binary star system located 123 light-years from the Sun in the southern constellation of Cetus. It has an apparent visual magnitude of +6.83, which puts it below the normal limit for visibility with the average naked eye. The star is drifting closer to the Earth with a heliocentric radial velocity of −51 km/s.
HD 2638 is a ternary star system system in the equatorial constellation of Cetus. The pair have an angular separation of 0.53″ along a position angle of 166.7°, as of 2015. This is system too faint to be visible to the naked eye, having a combined apparent visual magnitude of 9.44; a small telescope is required. The distance to this system is 179.5 light years based on parallax, and it is drifting further away with a radial velocity of +9.6 km/s. The magnitude 7.76 star HD 2567 forms a common proper motion companion to this pair at projected separation 839″.
YZ Ceti is a red dwarf star in the constellation Cetus. Although it is relatively close to the Sun at just 12 light years, this star cannot be seen with the naked eye. It is classified as a flare star that undergoes intermittent fluctuations in luminosity. YZ Ceti is about 13 percent the mass of the Sun and 17% of its radius.
HD 12039, also known as DK Ceti, is a variable star in the constellation of Cetus at a distance of 135 ly (41 pc). It is categorized as a BY Draconis variable because of luminosity changes caused by surface magnetic activity coupled with rotation of the star. The stellar classification G4V is similar to the Sun, indicating this is a main sequence star that is generating energy at its core through the thermonuclear fusion of hydrogen. The effective temperature of 5,585 K gives the star a yellow hue. It has about the same mass as the Sun, but only emits 89% of the Sun's luminosity. This is a young star with age estimates ranging from 7.5−8 million years to 30 million years.
HD 224693, also named Axólotl, is a star in the equatorial constellation of Cetus, and is positioned near the western constellation border with Aquarius. It can be viewed with a small telescope but is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.23. Based on parallax measurements, the object is located at a distance of approximately 306 light years from the Sun. It is drifting further away with a radial velocity of 1.5 km/s.
HD 41004 is a visual binary star system in the southern constellation of Pictor. It is too faint to be visible to the naked eye, having a combined apparent visual magnitude of 8.65. The two components have a magnitude difference of 3.7, and share a common proper motion with an angular separation of 0.30″, as of 2018. The distance to this system is approximately 127 light-years based on parallax. It is drifting further away from the Sun with a radial velocity of +42.5 km/s, having come to within 44.5 ly some 831,000 years ago.
HD 142415 is a single star in the southern constellation of Norma, positioned next to the southern constellation border with Triangulum Australe and less than a degree to the west of NGC 6025. With an apparent visual magnitude of 7.33, it is too faint to be visible to the naked eye. The distance to this star is 116 light years from the Sun based on parallax, but it is drifting closer with a radial velocity of −12 km/s. It is a candidate member of the NGC 1901 open cluster of stars.
HD 162020 is a star in the southern constellation of Scorpius with a likely red dwarf companion. It has an apparent visual magnitude of 9.10, which is too faint to be visible to the naked eye. The distance to this system is 102 light-years based on stellar parallax. It is drifting closer to the Sun with a radial velocity of −27 km/s, and is predicted to come to within ~18 light-years in 1.1 million years.
81 Ceti is a star located approximately 331 light years away from the Sun in the equatorial constellation of Cetus. 81 Ceti is the Flamsteed designation for this object. It is visible to the naked eye as a dim, yellow-hued point of light with an apparent visual magnitude of 5.65. The star is drifting further away from the Earth with a heliocentric radial velocity of +9 km/s.
HD 131664 is an 8th magnitude star in the southern constellation of Apus with an orbiting brown dwarf or stellar companion. Parallax measurements by the Gaia space observatory provide an estimated distance of 172.5 light years from the Earth. The system is moving further away with a baseline heliocentric radial velocity of +35 km/s.
HD 1461 b is an extrasolar planet, orbiting the 6th magnitude G-type star HD 1461, 76.5 light years away in the constellation Cetus. This planet has a minimum mass 6.4 times that of Earth and orbits at a distance of 0.0634 AU with an eccentricity of less than 0.131. It is currently unknown whether the planet is a gas giant like Uranus or Neptune, or has terrestrial composition like CoRoT-7b. This planet was announced on 13 December 2009 after it was discovered using radial velocity measurements taken at the Keck and Anglo-Australian Observatories.
75 Ceti is a single star in the equatorial constellation of Cetus with at least two planets. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of +5.36. The star is located 268 light-years distant from the Sun, based on parallax, but is drifting closer with a radial velocity of −6 km/s.
HD 93385 is a star in the southern constellation of Vela. At an apparent visual magnitude of 7.5, it is too faint to be seen with the unaided eye. Parallax measurements made using the Gaia spacecraft show an annual shift of 23.15 mas. This is equivalent to a physical separation of around 141 light years from the Sun. It is drifting further away with a radial velocity of +47.8 km/s.
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. The star is located at a distance of 71.65 light years from the Sun based on parallax. It is drifting closer with a radial velocity of −3.8 km/s.
9 Ceti is a star in the equatorial constellation of Cetus. It has the variable star designation BE Ceti, while 9 Ceti is the Flamsteed designation. It has an apparent visual magnitude of 6.4, which is below the limit that can be seen with the naked eye by a typical observer. Based upon parallax measurements, this star is 69.6 light years away from the Sun.
HD 167665 is a yellow-white hued star with a brown dwarf companion in the southern constellation of Sagittarius. With an apparent visual magnitude of 6.39, it is near the lower brightness limit for stars that are visible to the naked eye. Based upon an annual parallax shift of 32.4 mas as seen from Earth, it is located 101 light years from the Sun. The star is moving away from the Sun with a radial velocity of +8 km/s.
HD 189567 is a star with a pair of orbiting exoplanets, located in the southern constellation of Pavo. It is also known as Gliese 776, CD-67 2385, and HR 7644. The star has an apparent visual magnitude of 6.07, which is bright enough for it to be dimly visible to the naked eye. It lies at a distance of 58 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −10.5 km/s.
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