HD 81040 is a star in the equatorial constellation of Leo. With an apparent visual magnitude of +7.73 [2] it is too dim to be visible to the naked eye but can be viewed with a small telescope. The star is located at a distance of 112 light years from the Sun based on parallax. It is drifting further away with a radial velocity of +49 km/s, [3] having come to within 48 light-years some 527,000 years ago.
This is an ordinary G-type main-sequence star with a stellar classification of G0V. [2] The Sun somewhat dwarfs HD 81040 in terms of physical characteristics: it has 87% of the Sun's mass and 91% of the radius of the Sun. It is spinning with a projected rotational velocity of 5.3 km/s, [2] and has near solar metallicity. [4] The age of the star is not precisely known; the ELODIE spectrograph suggested 0.8 Gyr and found it to have a young dust disk. [9] Later measurements by modelling chromosperic activity suggested an age of 4.18 Gyr.[ citation needed ]
On November 24, 2005, a superjovian planet was announced by Sozzetti et al. [9] It was discovered using the radial velocity method. Astrometric measurements using Gaia , published in several papers, show that the inclination of its orbit is about 111 degrees, so its true mass is somewhat higher than that predicted from its minimum mass. [7] [5]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | 7.53±0.032 MJ | 1.946±0.014 | 1,004.7±3.0 | 0.525+0.024 −0.026 | 111.4+4.4 −4.7 ° | — |
HD 219134 is a main-sequence star in the constellation of Cassiopeia. It is smaller and less luminous than the Sun, with a spectral class of K3V, which makes it an orange-hued star. HD 219134 is relatively close to our system, with an estimated distance of 21.34 light years. This star is close to the limit of apparent magnitude that can still be seen by the unaided eye. The limit is considered to be magnitude 6 for most observers. This star has a magnitude 9.4 optical companion at an angular separation of 106.6 arcseconds.
HD 81040 b is a massive gas giant exoplanet that orbits the star HD 81040, discovered in 2005 by radial velocity. Its orbital period is just over 1000 days. It has a semimajor axis of about 1.95 AU, and its orbit is quite eccentric, at a little over 0.5.
HD 136118 is a star in the Serpens Caput section of the Serpens constellation. The star is too dim to be readily visible to the naked eye, having an apparent visual magnitude of 6.93. It is located at a distance of 165 light years from the Sun based on parallax, and is drifting closer with a radial velocity of −3 km/s.
HD 11506 is a star in the equatorial constellation of Cetus. It has a yellow hue and can be viewed with a small telescope but is too faint to be visible to the naked eye, having an apparent visual magnitude of 7.51. The distance to this object is 167 light years based on parallax, but it is drifting closer to the Sun with a radial velocity of −7.5 km/s. It has an absolute magnitude of 3.94.
HD 72659 is a star in the equatorial constellation of Hydra. With an apparent visual magnitude of 7.46, his yellow-hued star is too faint to be viewed with the naked eye. Parallax measurements provide a distance estimate of 169.4 light years from the Sun, and it has an absolute magnitude of 3.98. The star is drifting closer with a radial velocity of −18.3 km/s.
HD 73256 is a variable star in the southern constellation of Pyxis. It has the variable star designation CS Pyxidis. With a baseline apparent visual magnitude of 8.08, it requires binoculars or a small telescope to view. The star is located at a distance of 120 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +30 km/s.
HD 109749 is a binary star about 206 light years away in the constellation of Centaurus.
HD 179079 is a star with an exoplanetary companion in the equatorial constellation of Aquila. It has an apparent visual magnitude of approximately 7.96, making it too faint to be readily visible to the naked eye. The distance to this star can be determine using parallax measurements, which yields an estimate of approximately 228 light years. It is drifting further away with a radial velocity of +20 km/s.
HD 87883 is star in the northern constellation of Leo Minor. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 7.56. The star is located at a distance of 59.7 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +9.3 km/s. It has an absolute magnitude of 6.27.
HD 126614 is a trinary star system in the equatorial constellation of Virgo. The primary member, designated component A, is host to an exoplanetary companion. With an apparent visual magnitude of 8.81, it is too faint to be seen with the naked eye. The system is located at a distance of 239 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −33 km/s.
Gliese 179 is a small red dwarf star with an exoplanetary companion in the equatorial constellation of Orion. It is much too faint to be visible to the naked eye with an apparent visual magnitude of 11.94. The system is located at a distance of 40.5 light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of –9 km/s. It is a high proper motion star, traversing the celestial sphere at an angular rate of 0.370″·yr−1.
HD 175167 is a star with an exoplanet companion in the southern constellation of Pavo. It is too faint to be visible with the naked eye at an apparent visual magnitude of 8.01. The system is located at a distance of 232 light-years from the Sun based on parallax measurements, and it is drifting further away with a radial velocity of 5 km/s. It shows a high proper motion, traversing the celestial sphere at an angular rate of 0.190 arcsec yr−1.
HD 175167 b is an exoplanet orbiting HD 175167, which is a G type star within the Pavo constellation 232 light-years away from the Earth. The planet was discovered by the Magellan Planet Search Program as the astronomical object fit the Keplerian orbital model. During the observations 13 doppler velocity tests were conducted, which showed this object's mass was at least 7.8 Jovian-masses and its orbit has a high eccentricity. The exoplanet takes 3.53 years to complete a full stellar orbit.
HD 79498 is a primary of the star system located 159 light years away in the constellation Cancer. This G5 main sequence star has an apparent magnitude of 8.0 and is about the same size and mass as the Sun. It has a higher than solar abundance of elements other than hydrogen and helium; what astronomers term a metal-rich star.
HD 98649 is a G-type yellow dwarf star, classified as a G4V, that has approximately the same mass and diameter as the Sun, but has only 86% of its luminosity. It is considered a solar analog. HD 98649 is about 138 light-years from earth. HD 98649 is found in the Crater constellation.
HD 106515 is a binary star in the constellation of Virgo.
Mu2 Octantis (μ2 Oct) is a binary star system of two G-type main-sequence stars. It shares the designation μ with μ1 Octantis, from which it is separated by 50 arcminutes.
HD 222155 is a star in the northern constellation of Andromeda. It is a yellow star that can be viewed with binoculars or a small telescope, but is too faint to be seen with the naked eye at an apparent visual magnitude of 7.1. The imaging survey in 2017 did not detect any stellar companions to HD 222155.
HD 191806 is a star located in the northern constellation Cygnus. With an apparent magnitude of 8.093, it's undetectable with the naked eye, but can be seen with binoculars. HD 191806 is currently placed at a distance of 215 light years based on parallax measurements and is drifting towards the Solar System with a spectroscopic radial velocity of −15.28 km/s.