Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cancer [a] |
Right ascension | 08h 38m 45.52054s [1] |
Declination | +23° 41′ 09.2561″ [1] |
Apparent magnitude (V) | 6.876±0.032 [2] |
Characteristics | |
Evolutionary stage | Main sequence |
Spectral type | F6V [3] |
B−V color index | 0.547 [3] |
Astrometry | |
Radial velocity (Rv) | 6.28±0.13 [1] km/s |
Proper motion (μ) | RA: −47.495 mas/yr [1] Dec.: −148.502 mas/yr [1] |
Parallax (π) | 28.3757 ± 0.0213 mas [1] |
Distance | 114.94 ± 0.09 ly (35.24 ± 0.03 pc) [1] |
Absolute magnitude (MV) | 4.20 [4] |
Details [5] | |
Mass | 1.20±0.02 M☉ |
Radius | 1.22±0.04 R☉ |
Luminosity | 1.79 [6] L☉ |
Temperature | 6220±64 K |
Metallicity [Fe/H] | 0.18±0.043 dex |
Rotation | 9.09±0.04 d |
Age | 1.15+0.30 −0.33 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
HD 73344 is a star located in the constellation Cancer. It has a faint apparent magnitude of 6.9 and therefore can't be seen by the naked eye. It is located 35.2 parsecs (115 light-years) away based on parallax measurements. This star hosts three confirmed exoplanets.
HD 73344 is a F-type main-sequence star, a star hotter and brighter than the Sun that fuses atoms of hydrogen into helium at its core. It is 22% larger, 20% more massive [5] and 80% more luminous, [6] and its effective temperature is 448 degrees hotter, at 6,220 K (5,950 °C). On the other hand, it is younger than the Sun, estimated to be between one and two billion years old, or one-fifth to two-fifths of the solar age. As a consequence, HD 73344 rotates quickly, taking nine days to rotate at its equator (the Sun's rotational period is of 25 days [7] ), and is much more active than the Sun. [5]
Located at 35 parsecs (110 light-years ) from Earth, HD 73344 has an apparent magnitude, that is, its brightness as seen from Earth, of 6.876. Therefore, it is too faint to be seen to the naked eye, and needs a small telescope or binoculars to be seen. [1] [2] [8] [9] Distance and apparent brightness allow the absolute magnitude —the star's brightness if seen at 10 parsecs (33 light-years)—to be calculated at 4.2. [4] This star has a nearly circular orbit around the Milky Way, a maximum distance of 40 pc (130 ly) from the galactic plane and a distance from the Galactic Center varying from 6,880 to 8,840 parsecs (22,400 to 28,800 light-years) across its orbit. [4]
There are three exoplanets orbiting HD 73344, all discovered in 2024 via multiple methods of detection: Transit, radial velocity and astrometry. [10]
The planet's orbital periods range from two weeks to a decade and five years. They are all misaligned with each other: Planet b and c have a misalignment of at least 20 degrees, and planet d is misaligned with the inner planets' orbits, in contrast to the Solar System, where the planetary orbits are well aligned. There are two hypotheses that could explain the misalignment: A warped protoplanetary disk with misaligned inner and outer components, or dynamical encounters with two or more giant planets in the past. [10]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | 2.98+2.50 −1.90 M🜨 (<10.48 ME) | 0.131+0.0003 −0.0002 | 15.611 d | 0.030+0.019 −0.013 | 88.082°+0.051° −0.056° | 2.884+0.082 −0.072 R🜨 |
c | ≥0.367+0.022 −0.021 MJ | 0.343+0.0009 −0.0006 | 65.94±0.02 | 0.124+0.052 −0.053 | – | – |
d | 2.55+0.56 −0.46 MJ | 6.70+0.25 −0.26 | 15.95+0.85 −0.84 | 0.2±0.1 | 58°+19° −16° | – |
HD 73344 b was the first exoplanet discovered in the system, detected via the transit method by S. Sulis and others. It is classified a sub-Neptune. This planet has around three times the size of Earth as determined by transit observations. Its mass is uncertain, estimated at 3.0+2.5
−1.9 times Earth's mass and believed to be no more than ten Earth masses. This implies a low density of 0.68+0.59
−0.44 g/cm3 , suggesting that its atmosphere is composed of volatile elements like hydrogen and helium. However, further observations are needed, including a more precise mass, to fully characterize its composition and reveal its true nature. [5]
It is the closest exoplanet to HD 73344, completing an orbit every 16 days at an average distance of 0.131 astronomical units (19,600,000 km), less than half of the Mercury-Sun distance (0.31 AU). The proximity of its host star also mean it has a high temperature. Assuming a null albedo, the equilibrium temperature of HD 73344 b is estimated at 910 K (637 °C; 1,178 °F), or 1,066 K (793 °C; 1,459 °F) if it is tidally locked. [5] It has a low orbital eccentricity and appear to be misaligned with its star's spin axis. [10]
HD 73344 c is a sub-Saturn planet, first identified by Sulis et al. 2024 (the same discoverers of planet b) via radial velocity observations [5] and confirmed by Jingwen et al. some months later. [10] Its mass, derived via radial velocity observations, is at least 110 Earth masses, equivalent to 0.37 Jupiter masses (MJ), [10] and no more than 0.7 MJ, as a mass greater than this would induce an unstable planetary system. Since HD 73344 c does not transit its host star, its radius cannot be measured. [5]
This planet, like HD 73344 b, lies at a close distance to its host star, with an orbital period of 66 days and an average distance of 0.34 astronomical units, similar to Mercury. The orbital eccentricity is small, at 0.12±0.05, and the inclination is not precisely known, [10] but is no less than 30° [5] and is at least 20° different from planet b's inclination. [10] The equilibrium temperature is estimated to be 562 K (289 °C; 552 °F) assuming a null albedo. [5]
HD 73344 b and c are strongly coupled with each other and undergo nodal precession, meaning that their orbital inclinations vary over time, becoming sometimes misaligned with the host star's spin axis. [10]
HD 73344 d is a Jovian planet, first identified in 27-year baseline radial velocity observations from multiple observatories, and later in Hipparcos-Gaia astrometric observations. Its mass, measured via astrometry, is two and a half times the mass of Jupiter. [10]
This planet has a wide orbit around HD 73344, and if placed in our Solar System, would lie between that of Jupiter and Saturn, at 6.7 astronomical units. It takes 16 years to complete an orbit around HD 73344. HD 73344 d is therefore classified as a Jupiter analog due to their physical and orbital characteristics being similar. [10]
HD 179949 is a 6th magnitude star in the constellation of Sagittarius. It is a yellow-white dwarf, a type of star hotter and more luminous than the Sun. The star is located about 90 light years from Earth and might be visible under exceptionally good conditions to an experienced observer without technical aid; usually binoculars are needed.
HD 28185 is a single yellow dwarf star similar to the Sun, located 128 light-years away from Earth in the constellation Eridanus. The designation HD 28185 refers to its entry in the Henry Draper catalogue. The star is known to possess two long-period extrasolar planets.
HD 189733, also catalogued as V452 Vulpeculae, is a binary star system 64.5 light-years away in the constellation of Vulpecula. The primary star is suspected to be an orange dwarf star, while the secondary star is a red dwarf star. Given that this system has the same visual magnitude as HD 209458, it promises much for the study of close transiting extrasolar planets. The star can be found with binoculars 0.3 degrees east of the Dumbbell Nebula (M27).
HD 38529 is a binary star approximately 138 light-years away in the constellation of Orion.
HD 80606 and HD 80607 are two stars comprising a binary star system. They are approximately 217 light-years away in the constellation of Ursa Major. Both stars orbit each other at an average distance of 1,200 astronomical units. The binary system is listed as Struve 1341 in the Struve Catalogue of Double Stars; however, this designation is not in wide use and the system is usually referred to by the HD designations of its constituent stars. An extrasolar planet has been confirmed to orbit HD 80606 in a highly elliptical orbit.
HD 210702 is a star with an orbiting exoplanet in the northern constellation of Pegasus. It has an apparent visual magnitude of 5.93, which is bright enough that the star is dimly visible to the naked eye. The distance to HD 210702 is 177 light years based on parallax measurements, and it is drifting further away with a radial velocity of 18.5 km/s. It is a probable member of the Ursa Major moving group, an association of co-moving stars.
HD 43691 is a star with an orbiting exoplanet in the constellation Auriga. With an apparent visual magnitude of 8.03, it is too faint to be visible to the naked eye. This system is located at a distance of 279 light years based on parallax measurements, but is drifting closer with a heliocentric radial velocity of −29 km/s.
HD 117207 is a star in the southern constellation Centaurus. With an apparent visual magnitude of 7.24, it is too dim to be visible to the naked eye but can be seen with a small telescope. Based upon parallax measurements, it is located at a distance of 105.4 light-years from the Sun. The star is drifting closer with a radial velocity of −17.4 km/s. It has an absolute magnitude of 4.67.
HD 118203 is a star with an orbiting exoplanet located in the northern circumpolar constellation of Ursa Major. It has the proper name Liesma, which means flame, and it is the name of a character from the Latvian poem Staburags un Liesma. The name was selected in the NameExoWorlds campaign by Latvia, during the 100th anniversary of the IAU.
HD 141937 is a star in the southern zodiac constellation of Libra, positioned a couple of degrees to the north of Lambda Librae. It is a yellow-hued star with an apparent visual magnitude of 7.25, which means it is too faint to be seen with the naked eye. This object is located at a distance of 108.9 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −2.2 km/s. It has an absolute magnitude of 4.71.
XO-2 is a binary star system about 490 light-years away in the constellation Lynx. It consists of two components, XO-2N and XO-2S, both of which host planetary systems.
WASP-18 is a magnitude 9 star located 400 light-years away in the Phoenix constellation of the southern hemisphere. It has a mass of 1.29 solar masses.
HD 28254 is a binary star system located 180 light-years away in the constellation Dorado. The primary component is an 8th magnitude G-type main-sequence star. This star is larger, cooler, brighter, and more massive than the Sun, and its metal content is 2.3 times as much as the Sun. In 2009, a gas giant exoplanet was found in orbit around the star.
HD 190007, also known as Gliese 775, is a star with a close orbiting exoplanet in the constellation of Aquila. Parallax measurements by Gaia put the star at a distance of 41.5 light-years away from the Sun. It is drifting closer with a radial velocity of −30.3 km/s, and is predicted to come within 11.8 light-years in 375,000 years. The star has an absolute magnitude of 6.91, but at its present distance the apparent visual magnitude is 7.46, which is too faint to be viewed with the naked eye.
HD 181342 is a star with an orbiting exoplanet in the constellation of Sagittarius. With an apparent magnitude of 7.55, it cannot be seen with the naked eye. Parallax measurements made by Gaia spacecraft put the star at a distance of 394 light-years away. It is drifting closer with a heliocentric radial velocity of radial_v −0.8 km/s.
Kepler-21, also known as HD 179070, is a star with a closely orbiting exoplanet in the northern constellation of Lyra. At an apparent visual magnitude of 8.25 this was the brightest star observed by the Kepler spacecraft to host a validated planet until the discovery of an exoplanet orbiting HD 212657 in 2018. This system is located at a distance of 354 light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −18.2 km/s.
HD 1690 is a giant star with an orbiting exoplanet companion in the constellation of Cetus. It has an apparent visual magnitude of 9.19, which is too faint to be visible to the naked eye. The distance to this system is approximately 2,570 light years, and it is drifting further away with a radial velocity of +18.2 km/s. HD 1690 has no known companion star, making it a single star system.
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.
HD 201585 is a star located in the equatorial constellation Equuleus. It has an apparent magnitude of 8.23, making it readily visible in small telescopes but not to the naked eye. Gaia DR3 parallax measurements imply a distance of 594 light-years and it is currently receding with a heliocentric radial velocity of 14 km/s. At its current distance, HD 201585's brightness is diminished by three-tenths of a magnitudes due to interstellar extinction and it has an absolute magnitude of +1.81. HD 201585 is the star's Henry Draper Catalogue designation. It is also designated as MASCARA-1 meaning that it is the first star observed by the MASCARA exoplanet search program.
HD 76920 is a solitary orange-hued star with an orbiting exoplanetary companion in the southern constellation of Volans, close to the border with Carina. With an apparent magnitude of 7.82, it is too faint to be seen by the naked eye from Earth but is readily observable through binoculars. It is located at a distance of 597 light-years according to Gaia EDR3 parallax measurements, and is moving away at a heliocentric radial velocity of 20.09 km/s.