Location of HD 259431 (circled) near the bluish IC 447 nebulosity. NGC 2264 is below (west) and the Rosette Nebula on the right (south). Credit: ESO/S. Guisard | |
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Monoceros |
Right ascension | 06h 33m 05.19064s [1] |
Declination | +10° 19′ 19.9826″ [1] |
Apparent magnitude (V) | 8.62 - 8.91 [2] |
Characteristics | |
Spectral type | B6e [3] |
U−B color index | −0.540 [4] |
B−V color index | 0.286 [4] |
Variable type | Orion [2] |
Astrometry | |
Radial velocity (Rv) | 19.00 [5] km/s |
Proper motion (μ) | RA: −2.410 [1] mas/yr Dec.: −2.912 [1] mas/yr |
Parallax (π) | 1.5304 ± 0.0273 mas [1] |
Distance | 2,130 ± 40 ly (650 ± 10 pc) |
Details | |
Mass | 6.6 [6] M☉ |
Radius | 6.63 [6] R☉ |
Luminosity | 1,550 [6] L☉ |
Temperature | 14,125 [6] K |
Rotational velocity (v sin i) | 90 [7] km/s |
Age | 0.32 [6] Myr |
Other designations | |
Database references | |
SIMBAD | data |
HD 259431 (MWC 147 or V700 Monocerotis) is a young stellar object in the constellation of Monoceros.
HD 259431 lies in the northern portion of Monoceros, between Orion and Canis Minor, along with the spectacular Rosette Nebula and NGC 2264 region. It is half a degree from the faint IC 447 reflection nebula.
HD 259431 is seen against NGC 2247, a small reflection nebula and star-forming region. It has been considered to be the illuminating source for the nebula, although it is uncertain if they are at the same distance. The Hipparcos annual parallax gives a distance of 170 parsecs [8] while NGC 2247 is thought to be at about 800 parsecs, although both distances are somewhat uncertain. [9] Many of its properties have been calculated assuming a distance of 800 parsecs, which means they are also highly uncertain. [3] Gaia Data Release 3 gives a statistically precise distance around 650 parsecs. [1]
HD 259431 is classed as a Herbig Haro Be star and has been instrumental in helping astronomers understand the formation of stars. [6] A large star, with a large surrounding dust cloud, [7] MWC 147 has given astronomers a clear picture of the mechanics of the accretion processes that form stars. [11]
Star MWC 147 was observed in the near and mid-infrared. The near-infrared studies showed dust matter at a temperature of several thousand kelvins in the innermost regions of the protoplanetary disk. In the mid-IR were lower temperatures. These observations showed that the disk around the star disk extends over 100 AU.
The resulting research model assumes that the star increasing in mass at a rate 7×10−6 solar masses per year, or the equivalent of about two Earth masses per year. MWC has a mass of 6.6 M☉ and is younger than 500 000 years. This means that the life of this star is expected to be only about 35 million years.[ citation needed ]
The star is found in the night sky at RA 06 h 33 m 05.19 and Dec 10° 19' 19.9869". It has a temperature of 14 125 K and spectral type of B6ep. It is also known as 2MJ06330519 + 1019199, HD 259431, HIP 31235 and SAO 95823.
R Monocerotis, abbreviated R Mon, is a very young binary star system in the equatorial constellation of Monoceros. The apparent magnitude of R Mon varies between 10 and 12 and the spectral type is B8IIIe.
R Coronae Australis is a variable binary system in the constellation Corona Australis. It has varied between magnitudes 10 and 14.36. A small reflection/emission nebula NGC 6729 extends from the star towards SE. It is also the brightest feature of the Coronet Cluster, therefore sometimes called R CrA Cluster.
V380 Ori is a young multiple star system located near the Orion Nebula in the constellation Orion, thought to be somewhere between 1 and 3 million years old. It lies at the centre of NGC 1999 and is the primary source lighting up this and other nebulae in the region.
S Monocerotis, also known as 15 Monocerotis, is a massive multiple and variable star system located in the constellation Monoceros. It is the brightest star in the Christmas Tree open cluster in the area catalogued as NGC 2264.
HD 110432 is a Be star in the south-east of Crux, behind the center of the southern hemisphere's dark Coalsack Nebula. It has a stellar classification of B1IVe, which means it is a subgiant star of class B that displays emission lines in its spectrum. This is a variable star of the Gamma Cassiopeiae type, indicating it is a shell star with a circumstellar disk of gas about the equator, and has the variable star designation BZ Crucis. It is not known to be a member of a binary system, although it is probably a member of the open cluster NGC 4609. This star is moderately luminous in the X-ray band, with a variable energy emission of 1032–33 erg s−1 in the range 0.2−12 keV. The X-ray emission may be caused by magnetic activity, or possibly by accretion onto a white dwarf companion.
MWC 349 is a double star system in the constellation Cygnus. Its properties are still debated and it may be a massive highly luminous star or a very young less luminous Herbig Ae/Be star. MWC 349 is also a variable star with the designation V1478 Cygni.
HD 168625 is a blue hypergiant star and candidate luminous blue variable located in the constellation of Sagittarius easy to see with amateur telescopes. It forms a visual pair with the also blue hypergiant HD 168607 and is located to the south-east of M17, the Omega Nebula.
13 Monocerotis is a class A0 Ib star in the constellation Monoceros. Its apparent magnitude is 4.5 and it is approximately 780 parsecs (2,500 ly) away.
HD 41742/41700 is a star system that lies approximately 88 light-years away in the constellation of Puppis. The system consists of two bright stars where the primary is orbited by two fainter stars, making it a quadruple with an unequal hierarchy.
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.
MWC 480 is a single star, about 500 light-years away in the constellation of Auriga. It is located in the Taurus-Auriga Star-Forming Region. The name refers to the Mount Wilson Catalog of B and A stars with bright hydrogen lines in their spectra. With an apparent magnitude of 7.62, it is too faint to be seen with the naked eye.
HD 65750, also known as V341 Carinae is a bright red giant star in the constellation Carina. It is surrounded by a prominent reflection nebula, known as IC 2220, nicknamed the Toby Jug Nebula.
HD 183143 is a blue hypergiant star located in the constellation of Sagitta.
HD 36112. also known as MWC 758, is a young Herbig Ae star located in the constellation Taurus, surrounded by irregular rings of cosmic dust. The system is about 3.5 million years old. The disk has a cavity at 50 astronomical units and two spiral arms at 30-75 au that are seen in near-infrared scattered light, but only one spiral arm is seen in ALMA images.
HD 111395 is a single, variable star in the northern constellation of Coma Berenices. It has the variable star designation LW Com, short for LW Comae Berenices; HD 111395 is the Henry Draper Catalogue designation. The star has a yellow hue and is just bright enough to be barely visible to the naked eye with an apparent visual magnitude that fluctuates around 6.29. Based upon parallax measurements, it is located at a distance of 55.8 light years from the Sun. The star is drifting closer with a radial velocity of −8.9 km/s. It is a member of the Eta Chamaeleontis stellar kinematic group.
HD 53367 is a triple star system in the constellation of Monoceros. The primary star was identified as a variable Herbig Ae/Be star in 1989. Its companion, spectroscopically discovered in 2006, is a pre-main-sequence star star with an average separation of 1.7 AU. The star system is embedded in the extended nebula IC 2177.
V1794 Cygni is a single variable star in the northern constellation Cygnus. It has the identifier HD 199178 from the Henry Draper Catalogue; V1794 Cygni is its variable star designation. With an apparent visual magnitude of 7.24, it's too dim to be visible with the naked eye but can be seen with binoculars. V1794 is located at a distance of 367 light-years (113 pc) based on parallax measurements, but is drifting closer to the Sun with a radial velocity of −31 km/s. It lies superimposed over a region of faint nebulosity to the west of the North American Nebula.
HD 150193 is a binary star system in the constellation of Ophiuchus. The primary star was identified as a Herbig Ae/Be star with a strong solar wind, losing approximately a tenth of solar mass per million years. It does host a very small debris disk, likely due to disk truncation by the nearby stellar companion. The disk is inclined 38±9° to the plane of sky. It appears to be highly evolved and asymmetric, with indications of flattening and grains growth.
HD 104237 is a candidate multiple star system in the southern constellation of Chamaeleon. It has the variable star designation DX Chamaeleontis, abbreviated DX Cha; HD 104237 is the stellar designation from the Henry Draper Catalogue. The system is dimly visible to the naked eye with an apparent visual magnitude that ranges from 6.59 down to 6.70. It is located at a distance of approximately 348 light-years from the Sun based on parallax measurements. The system is positioned just 2′ to the north-east of the 5th magnitude star Epsilon Chamaeleontis, and is a member of the ε Cha association of co-moving stars.
CQ Tauri is a young variable star in the equatorial constellation of Taurus. It is too faint to be visible to the naked eye with an apparent visual magnitude that ranges from 8.7 to 12.25. The distance to this star is approximately 487 light years based on parallax measurements, and it is drifting further away with a radial velocity of ~23 km/s. It appears to be part of the T-association Tau 4. CQ Tauri lies close enough to the ecliptic to undergo lunar occultations.