Notes
- ↑ From , where is the luminosity, is the radius, is the effective surface temperature and is the Stefan–Boltzmann constant.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 12h 53m 11.1564s [1] |
| Declination | −03° 33′ 11.1482″ [1] |
| Apparent magnitude (V) | 6.11 |
| Characteristics | |
| Spectral type | F6V [2] |
| B−V color index | 0.49 [2] |
| Astrometry | |
| Proper motion (μ) | RA: −262.638±0.113 [1] mas/yr Dec.: −3.853±0.100 [1] mas/yr |
| Parallax (π) | 30.0702 ± 0.0541 mas [1] |
| Distance | 108.5 ± 0.2 ly (33.26 ± 0.06 pc) |
| Details | |
| Mass | 1.18 ± 0.12 [2] M☉ |
| Radius | 1.45 ± 0.07 [2] R☉ |
| Luminosity | 3.48 [note 1] L☉ |
| Temperature | 6557 ± 96 [2] K |
| Metallicity [Fe/H] | 0.07 [2] dex |
| Age | 1.9+0.6 −0.7 [2] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
38 Virginis is an F-type main sequence star in the constellation of Virgo. It is around 108 light years distant from the Earth. [2] [1]
The name 38 Virginis derives from the star being the 38th star in order of right ascension catalogued in the constellation Virgo by Flamsteed in his star catalogue. The designation b of 38 Virginis b derives from the order of discovery and is given to the first planet orbiting a given star, followed by the other lowercase letters of the alphabet. [4] In the case of 38 Virginis, only one was discovered, which was designated b. [2]
38 Virginis is an F-type main sequence star that is approximately 118% the mass of and 145% the radius of the Sun. It has a temperature of 6557 K and is about 1.9 billion years old. In comparison, the Sun is about 4.6 billion years old [5] and has a temperature of 5778 K. [6]
The star is metal-rich, with a metallicity ([Fe/H]) of 0.07 dex, or 117% the solar amount. Its luminosity (L☉) is 3.48 times that of the Sun.
A companion star is cataloged in the CCDM at a separation of half an arcsecond. [7]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 4.51 ± 0.5 MJ | 1.82 ± 0.07 | 825.9 ± 6.2 | 0.03 ± 0.04 | — | — |
The star is known to host one exoplanet, 38 Virginis b, discovered in 2016. This planet has a relatively low eccentricity out of any long-period giant exoplanet discovered, with an eccentricity of 0.03. The planet has a mass of around 4.5 times that of the planet Jupiter. [2] Its orbit very likely puts it and any moons it may have in the habitable zone of its star.[ citation needed ]
70 Virginis is a binary star located 59 light years from the Sun in the equatorial constellation of Virgo, near the northern constellation border with Coma Berenices. 70 Virginis is its Flamsteed designation. The star is visible to the naked eye as a faint, yellow-hued point of light with an apparent visual magnitude of +4.97. It is drifting further away with a heliocentric radial velocity of +4.4 km/s and has a high proper motion, traversing the celestial sphere at the rate of 0.621 arc seconds per annum.
47 Ursae Majoris, formally named Chalawan, is a yellow dwarf star approximately 45.3 light-years from Earth in the constellation of Ursa Major. As of 2011, three extrasolar planets are believed to orbit the star.
HD 150706 is a star with an orbiting exoplanet in the northern constellation of Ursa Minor. It is located 92 light years away from the Sun, based on parallax measurements. At that distance, it is not visible to the unaided eye. However, with an apparent visual magnitude of 7.02, it is an easy target for binoculars. It is located only about 10° from the northern celestial pole so it is always visible in the northern hemisphere except for near the equator. Likewise, it is never visible in most of the southern hemisphere. The star is drifting closer to the Sun with a radial velocity of −17.2 km/s.
HD 20367 is a star in the constellation of Aries, close to the border with the Perseus constellation. It is a yellow-white hued star that is a challenge to view with the naked eye, having an apparent visual magnitude of 6.40. Based upon parallax measurements, it is located 85 light years from the Sun. It is drifting further away with a radial velocity of +6.5 km/s. Based upon its movement through space, it is a candidate member of the Ursa Major Moving Group of co-moving stars that probably share a common origin.
HD 130322 is a star with a close orbiting exoplanet in the constellation of Virgo. The distance to this system is 104 light years, as determined using parallax measurements. It is drifting closer to the Sun with a radial velocity of −12.4 km/s. With an apparent visual magnitude of 8.04, it is too dim to be visible to the naked eye; requiring binoculars or a small telescope to view. Being almost exactly on the celestial equator the star is visible everywhere in the world except for the North Pole. The star shows a high proper motion, traversing the celestial sphere at an angular rate of 0.197 arcsec yr−1.
Chi Virginis is a double star in the constellation Virgo. Based upon parallax measurements, it is approximately 315 light-years from Earth. It has an apparent visual magnitude of 4.65, which is bright enough to be seen with the unaided eye under suitable viewing conditions.
TW Hydrae is a T Tauri star approximately 196 light-years away in the constellation of Hydra. TW Hydrae is about 80% of the mass of the Sun, but is only about 5-10 million years old. The star appears to be accreting from a face-on protoplanetary disk of dust and gas, which has been resolved in images from the ALMA observatory. TW Hydrae is accompanied by about twenty other low-mass stars with similar ages and spatial motions, comprising the "TW Hydrae association" or TWA, one of the closest regions of recent "fossil" star-formation to the Sun.
Gliese 667 is a triple-star system in the constellation Scorpius lying at a distance of about 7.2 parsecs from Earth. All three of the stars have masses smaller than the Sun. There is a 12th-magnitude star close to the other three, but it is not gravitationally bound to the system. To the naked eye, the system appears to be a single faint star of magnitude 5.89.
HD 20782 is the primary of a wide binary system located in the southern constellation Fornax. It has an apparent magnitude of 7.38, making it readily visible in binoculars but not to the naked eye. The system is located relatively close at a distance of 117 light-years based on Gaia DR3 parallax measurements, but it is receding with a heliocentric radial velocity of 40.7 km/s. At its current distance, HD 20782's brightness is diminished by 0.12 magnitudes due to interstellar extinction and it has an absolute magnitude of +4.61.
HD 23596 is a star with an orbiting exoplanet companion in the constellation Perseus. It has an apparent visual magnitude of 7.25, which is too dim to be viewed with the naked eye. Based on parallax measurements, it is located at a distance of 169 light years from the Sun. The system is drifting closer with a radial velocity of −10 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 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.
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.
TW Hydrae b is a likely extrasolar planet orbiting the young T Tauri star TW Hydrae approximately 176 light-years (54 parsecs, or nearly 1.665×1016 km) away in the constellation of Hydra. It is likely a Neptune-like planet orbiting at a distance of nearly 22 AU from its star.
HD 85512 is a solitary K-type main-sequence star 36.8 light-years away in the constellation Vela. It is about 1 billion years older than the Sun. It is extremely chromospherically inactive, only slightly more active than Tau Ceti. It exhibits a long-term variability and was thought to host one low-mass planet, although this is now doubtful.
HD 221287 b, also known as Pipitea, is an exoplanet that orbits HD 221287, approximately 173 light years away in the constellation of Tucana. This planet has mass >3.12 MJ and orbits in a habitable zone at 1.25 AUs from the star, taking 1.25 years to orbit at 29.9 km/s around the star. Dominique Naef discovered this planet in early 2007 by using HARPS spectrograph located in Chile.
Gliese 667 Cc is an exoplanet orbiting within the habitable zone of the red dwarf star Gliese 667 C, which is a member of the Gliese 667 triple star system, approximately 23.62 light-years away in the constellation of Scorpius. The exoplanet was found by using the radial velocity method, from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star.
11 Comae Berenices is a binary star system in the northern constellation of Coma Berenices, located in the sky, east and slightly north of Denebola in Leo, but not nearly as far east as ε Virginis in Virgo. It is about a degree from the elliptical galaxy M85 and two degrees north of the spiral galaxy M100. Based upon an annual parallax shift of 10.7104 mas, the star is located 305 light years away from the Sun. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.72. This body is moving away from the Sun with a heliocentric radial velocity of +44 km/s.
RR Caeli is an eclipsing binary star in the constellation Caelum. It is 69 light years from Earth.
38 Virginis b is a super-Jupiter exoplanet orbiting within the habitable zone of the star 38 Virginis about 108.5 light-years from Earth in the constellation Virgo. The exoplanet was found by using the radial velocity method, from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star.
