Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Lupus |
Right ascension | 15h 15m 48.4460s [1] |
Declination | −37° 09′ 16.024″ [1] |
Apparent magnitude (V) | 8.708 [2] |
Characteristics | |
Spectral type | F8V [2] |
Astrometry | |
Proper motion (μ) | RA: −19.210 [1] mas/yr Dec.: −23.268 [1] mas/yr |
Parallax (π) | 7.4074 ± 0.0159 mas [1] |
Distance | 440.3 ± 0.9 ly (135.0 ± 0.3 pc) |
Details | |
Mass | 1.5 [1] M☉ |
Radius | 2.1 [1] R☉ |
Luminosity | 6.4 [1] L☉ |
Surface gravity (log g) | 3.80 [1] cgs |
Temperature | 6,313 [1] K |
Age | 10.5 [3] Myr |
Other designations | |
Database references | |
SIMBAD | data |
SAO 206462 is a young binary star, surrounded by a circumstellar disc of gas and clearly defined spiral arms. It is situated about 440 light-years away from Earth in the constellation Lupus. [4] The presence of these spiral arms seems to be related to the existence of planets inside the disk of gas surrounding the star. The disk's diameter is about twice the size of the orbit of Pluto. [5]
The discovery of this object was presented in October 2011 by Carol Grady, astronomer of Eureka Scientific, headquartered in the Goddard Space Flight Center at NASA. It was the first of this class that exhibited a high degree of clarity and was made using several space telescopes (Hubble, FUSE, Spitzer) and earth telescopes (Gemini Observatory and Subaru Telescope, situated in Hawaii), through an international research program of young stars and of stars with planets. A number of astronomers of different observatories collaborated. [6]
The pair of spiral arms around SAO 206462 have a rotation rate of −0.85 degrees per year, which are thought to be caused by a dynamically driving protoplanet within the disk, at a distance of 66±3 astronomical units and an orbital period of 424±25 years. This planet should be a challenge to be detected using direct imaging due to the presence of dust particles obscuring it, but could be detected and confirmed via high-resolucion spectroscopic observations. [7]
Another planet candidate around SAO 206462 has been detected using observations of the JWST's NIRCam imaging instrument, with low signal-to-noise ratio, a mass of 0.8±0.3 MJ and a separation of 300 astronomical units. It has been dubbed CC1 (Companion candidate 1). Objects more massive than 2.2 MJ at distance of 120 AU have been ruled out by the observations. [8]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (years) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b(unconfirmed) | — | 66±3 | 424±25 | — | — | — |
CC1(unconfirmed) | 0.8±0.3 MJ | 300.8+9.9 −9.5 | — | — | — | — |
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Gomez's Hamburger, also known as IRAS 18059-3211 or Gomez's Whopper is an astronomical object believed to be a young A-type star surrounded by a protoplanetary disk. It was initially identified as a planetary nebula, and its distance was estimated to be approximately 6500 light-years away from Earth. However, recent results suggest that this object is a young star surrounded by a protoplanetary disk, at a distance of about 900 light-years away.
AU Microscopii is a young red dwarf star located 31.7 light-years away – about 8 times as far as the closest star after the Sun. The apparent visual magnitude of AU Microscopii is 8.73, which is too dim to be seen with the naked eye. It was given this designation because it is in the southern constellation Microscopium and is a variable star. Like β Pictoris, AU Microscopii has a circumstellar disk of dust known as a debris disk and at least two exoplanets, with the presence of an additional two planets being likely.
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HD 100546, also known as KR Muscae, is a pre-main sequence star of spectral type B8 to A0 located 353 light-years from Earth in the southern constellation of Musca. The star is surrounded by a circumstellar disk from a distance of 0.2 to 4 AU, and again from 13 AU out to a few hundred AU, with evidence for a protoplanet forming at a distance of around 47 AU.
HD 97048 or CU Chamaeleontis is a Herbig Ae/Be star 603 ly away in the constellation Chamaeleon. It is a variable star embedded in a dust cloud containing a stellar nursery, and is itself surrounded by a dust disk.
HD 141569 is an isolated Herbig Ae/Be star of spectral class A2Ve approximately 364 light-years away in the constellation of Libra. The primary star has two red dwarf companions at about nine arcseconds. In 1999, a protoplanetary disk was discovered around the star. A gap in the disk led to speculation about a possible extrasolar planet forming in the disk.
HR 8799 is a roughly 30 million-year-old main-sequence star located 133.3 light-years away from Earth in the constellation of Pegasus. It has roughly 1.5 times the Sun's mass and 4.9 times its luminosity. It is part of a system that also contains a debris disk and at least four massive planets. These planets were the first exoplanets whose orbital motion was confirmed by direct imaging. The star is a Gamma Doradus variable: its luminosity changes because of non-radial pulsations of its surface. The star is also classified as a Lambda Boötis star, which means its surface layers are depleted in iron peak elements. It is the only known star which is simultaneously a Gamma Doradus variable, a Lambda Boötis type, and a Vega-like star.
Fomalhaut b, formally named Dagon, is a former candidate planet observed near the A-type main-sequence star Fomalhaut, approximately 25 light-years away in the constellation of Piscis Austrinus. The object's discovery was initially announced in 2008 and confirmed in 2012 via images taken with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. Under the working hypothesis that the object was a planet, it was reported in January 2013 that it had a highly elliptical orbit with a period of 1,700 Earth years. The object was one of those selected by the International Astronomical Union as part of NameExoWorlds, their public process for giving proper names to exoplanets. The process involved public nomination and voting for the new name. In December 2015, the IAU announced the winning name was Dagon.
AB Aurigae is a young Herbig Ae star in the Auriga constellation. It is located at a distance of approximately 509 light years from the Sun based on stellar parallax. This pre-main-sequence star has a stellar classification of A0Ve, matching an A-type main-sequence star with emission lines in the spectrum. It has 2.4 times the mass of the Sun and is radiating 38 times the Sun's luminosity from its photosphere at an effective temperature of 9,772 K. The radio emission from the system suggests the presence of a thermal jet originating from the star with a velocity of 300 km s−1. This is causing an estimated mass loss of 1.7×10−8 M☉ yr−1.
HD 142527 is a binary star system in the constellation of Lupus. The primary star belongs to the Herbig Ae/Be star class, while the companion, discovered in 2012, is a red dwarf star or accreting protoplanet with a projected separation of less than 0.1″. The system is notable for its circumbinary protoplanetary disk and its discovery has helped refine models of planet formation. The orbit of companion is strongly inclined to the circumbinary protoplanetary disk.
HD 169142 is a single Herbig Ae/Be star. Its surface temperature is 7650±150 K. HD 169142 is depleted of heavy elements compared to the Sun, with a metallicity Fe/H index of −0.375±0.125, but is much younger at an age of 7.5±4.5 million years. The star is rotating slowly and has relatively low stellar activity for a Herbig Ae/Be star.
LkCa 15 is a T Tauri star in the Taurus Molecular Cloud. These types of stars are relatively young pre-main-sequence stars that show irregular variations in brightness. It has a mass that is about 97% of the Sun, an effective temperature of 4370 K, and is slightly cooler than the Sun. Its apparent magnitude is 11.91, meaning it is not visible to the naked eye.
PDS 70 is a very young T Tauri star in the constellation Centaurus. Located 370 light-years from Earth, it has a mass of 0.76 M☉ and is approximately 5.4 million years old. The star has a protoplanetary disk containing two nascent exoplanets, named PDS 70b and PDS 70c, which have been directly imaged by the European Southern Observatory's Very Large Telescope. PDS 70b was the first confirmed protoplanet to be directly imaged.
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A circumplanetary disk is a torus, pancake or ring-shaped accumulation of matter composed of gas, dust, planetesimals, asteroids or collision fragments in orbit around a planet. They are reservoirs of material out of which moons may form. Such a disk can manifest itself in various ways.
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