HD 49933

Last updated
HD 49933
Observation data
Epoch J2000       Equinox J2000
Constellation Monoceros
Right ascension 06h 50m 49.83180s [1]
Declination –00° 32′ 27.1701″ [1]
Apparent magnitude  (V)5.781 [2]
Characteristics
HD 49993 A
Spectral type F2 V [3]
U−B color index –0.07 [4]
B−V color index +0.39 [4]
HD 49993 B
Spectral type M0 [5]
Astrometry
Radial velocity (Rv)–14.7 [6]  km/s
Proper motion (μ)RA: +22.09 [1]   mas/yr
Dec.: –186.51 [1]   mas/yr
Parallax (π)33.69 ± 0.42  mas [1]
Distance 97 ± 1  ly
(29.7 ± 0.4  pc)
Absolute magnitude  (MV)3.42 [2]
Position (relative to HD 49933 A) [5]
ComponentHD 49933 B
Epoch of observation 2016
Angular distance 6.5″
Position angle 23°
Projected separation 190 AU
Details
Mass 1.079 ± 0.073 [7]   M☉
Radius 1.385 ± 0.031 [7]   R☉
Luminosity 3.47 ± 0.18 [7]   L☉
Surface gravity (log g)4.08 [8]   cgs
Temperature 6,598 [8]   K
Metallicity [Fe/H]–0.29 [8]   dex
Rotational velocity (v sin i)10 [9]  km/s
Age 2.4 [2]   Gyr
Other designations
BD −00 1462, HD  49933, HIP  32851, HR 2530, SAO  133760. [10]
Database references
SIMBAD data

HD 49933 (HR 2530) is a binary star system in the equatorial constellation of Monoceros, the unicorn. The HD designation indicates the identifier of the star found in the Henry Draper catalogue. At an apparent magnitude of 5.8, [2] this star can just be seen with the naked eye under suitably dark conditions. Based upon parallax measurements from the Hipparcos mission, [11] the distance to HD 49933 is about 97 light-years (30 parsecs ) with a 1% margin of error.

Contents

HD 49933 A

Its primary HD 49993 A is a Sun-like [7] star. This is an F-type main sequence star with a stellar classification of F2 V, [3] where the luminosity class V indicates that it is generating energy through the nuclear fusion of hydrogen at its core. It is slightly larger than the Sun, with 108% of the Sun's mass and 139% of the Sun's radius. HD 49933 A emits 3.47 times as much energy as the Sun from its outer atmosphere at a higher effective temperature of about 6,598 K, [7] giving it the yellow-white hue of an F-type star. [12] It is estimated to be 2.4 billion years old. [2]

The surface magnetic activity on this star is similar to what is observed on the Sun. Magnetic features on the surface have been detected using asteroseismology that appear to be starspots (the stellar equivalent to sunspots on the Sun). [13]

HD 49933 B

In 2008 it was discovered the primary star has an 11.3 magnitude common proper motion companion at an angular separation of 5.9  arcseconds, which may make this a binary star system if the pair are gravitationally bound. [14] In 2016, it was confirmed that HD 49933 A is orbited by a red dwarf star of spectral class M0. [5]

Related Research Articles

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<span class="mw-page-title-main">Tau Virginis</span> Star in the constellation Virgo

Tau Virginis is a single star in the zodiac constellation Virgo. With an apparent visual magnitude of 4.28, it is faintly visible to the naked eye. The distance to Tau Virginis, based upon parallax measurements, is approximately 225 light years with a margin of error of ±3 light years.

<span class="mw-page-title-main">PP Carinae</span> Star in the constellation Carina

p Carinae is the Bayer designation of a star in the southern constellation of Carina. It has the variable star designation PP Carinae and, at an apparent visual magnitude of +3.3, is readily visible to the naked eye from the southern hemisphere. From the observed parallax shift of this star as the Earth orbits the Sun, its distance can be estimated as roughly 480 light-years with a 6% margin of error. It is considered to be a member of the open cluster IC 2602 although it lies well outside the core visible group of stars.

HD 125288 is a single star in the southern constellation of Centaurus. It has the Bayer designation v Centauri ; while HD 125288 is the star's identifier in the Henry Draper catalogue. The object has a blue-white hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.30. Based on parallax measurements, it is located at a distance of approximately 1,230 light years from the Sun. This is a candidate runaway star that is moving to the west and falling back into the Galactic plane. It has an absolute magnitude of −3.56.

<span class="mw-page-title-main">HD 100673</span> Be star in the constellation Centaurus

A Centauri is a single star in the southern constellation of Centaurus. It is blue-white in hue and is faintly visible to the naked eye with an apparent visual magnitude of +4.62. The star is located at a distance of approximately 430 light-years from the Sun based on stellar parallax. It appears to be drifting further away with a radial velocity of around +6 km/s.

Nu2 Columbae is a solitary star in the southern constellation of Columba. It can be seen with the naked eye, having an apparent visual magnitude of 5.31. With an annual parallax shift of 24.51 mas, it is estimated to lie about 133 light years from the Sun.

Theta1 Crucis is a spectroscopic binary star system in the southern constellation of Crux. It is visible to the naked eye with an apparent visual magnitude of 4.30m. The distance to this star, as determined using parallax measurements, is around 235 light years.

<span class="mw-page-title-main">HD 153261</span> Star in the constellation Ara

HD 153261 is the Henry Draper Catalogue designation for a star in the southern constellation of Ara. It has an apparent visual magnitude of 6.137, placing it near the threshold of naked eye visibility. According to the Bortle Dark-Sky Scale, it can be viewed from dark suburban or rural skies. Based upon an annual parallax shift of just 2.32 mas, it is located at a distance of around 1,400 light-years from Earth.

HD 130917 is a single star in the northern constellation of Boötes. It is an A-type main sequence star with a stellar classification of A4V. At an apparent magnitude of 5.80, it is visible to the naked eye.

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<span class="mw-page-title-main">HD 106112</span> Dwarf star in the constellation Camelopardalis

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<span class="mw-page-title-main">Epsilon Pyxidis</span> Quadruple star system in the constellation Pyxis

Epsilon Pyxidis (ε Pyxidis) is quadruple star system in the southern constellation of Pyxis. It is faintly visible to the naked eye, having a combined apparent visual magnitude of +5.60. Based upon an annual parallax shift of 15.39 mas as seen from Earth, it is located around 212 light years from the Sun. The system is deemed to be a member of the Sirius supercluster of stars that share a common motion through space.

<span class="mw-page-title-main">Rho Piscium</span> Star in the constellation Pisces

Rho Piscium is a solitary, yellow-hued star in the zodiac constellation of Pisces. With an apparent visual magnitude of +5.34, it is faintly visible to the naked eye. Based upon an annual parallax shift of 39.66 mas as seen from Earth, it is located 82 light years from the Sun. It is a member of the thin disk population of the Milky Way.

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<span class="mw-page-title-main">V518 Carinae</span> Blue-hued variable star in the constellation Carina

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20 Ceti is a single star located around 590 light years away in the equatorial constellation of Cetus. It is faintly visible to the naked eye with apparent magnitude is 4.76. The Bright Star Catalogue has this star classified as M0III, matching an aging red giant star that has consumed the hydrogen at its core and expanded. Houk and Swift (1999) listed an earlier class of K5 III. It has around 60 times the Sun's radius and is radiating about 800 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,700 K.

102 Herculis is a single star in the northern constellation of Hercules. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude of 4.37. Based upon parallax measurements, it is located around 920 light years away from the Sun. The star is moving closer to the Earth with a heliocentric radial velocity of −15 km/s.

<span class="mw-page-title-main">Eta Delphini</span> Star in the constellation Delphinus

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139 Tauri is a single, blue-white hued star in the zodiac constellation of Taurus. It is faintly visible to the naked eye with an apparent visual magnitude of 4.81. The distance to this star, as determined from an annual parallax shift of 2.10±0.19 mas, is roughly 1,600 light years. Because this star is located near the ecliptic, it is subject to occultations by the Moon. One such event was observed April 28, 1990.

References

  1. 1 2 3 4 5 van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752 . Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID   18759600.
  2. 1 2 3 4 5 Holmberg, J.; Nordström, B.; Andersen, J. (July 2009). "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics". Astronomy and Astrophysics Supplement Series. 501 (3): 941–947. arXiv: 0811.3982 . Bibcode:2009A&A...501..941H. doi:10.1051/0004-6361/200811191. S2CID   118577511.Note: see VizieR catalogue V/130.
  3. 1 2 Malaroda, S. (August 1975). "Study of the F-type stars. I. MK spectral types". Astronomical Journal. 80: 637–641. Bibcode:1975AJ.....80..637M. doi: 10.1086/111786 .
  4. 1 2 Johnson, H. L.; et al. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode:1966CoLPL...4...99J.
  5. 1 2 3 Scholz, R.-D. (2016). "Overlooked wide companions of nearby F stars". Astronomy & Astrophysics. 587: A51. arXiv: 1601.01896 . Bibcode:2016A&A...587A..51S. doi:10.1051/0004-6361/201527965. S2CID   118348424.
  6. ↑ Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Carnegie Institute Washington D.C. Publication. Carnegie Institution of Washington. Bibcode:1953GCRV..C......0W.
  7. 1 2 3 4 5 Bruntt, H. (October 2009). "Accurate fundamental parameters of CoRoT asteroseismic targets. The solar-like stars HD 49933, HD 175726, HD 181420, and HD 181906". Astronomy and Astrophysics. 506 (1): 235–244. arXiv: 0907.1198 . Bibcode:2009A&A...506..235B. doi:10.1051/0004-6361/200911925. S2CID   17400417.
  8. 1 2 3 Cenarro, A. J.; et al. (January 2007). "Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters". Monthly Notices of the Royal Astronomical Society . 374 (2): 664–690. arXiv: astro-ph/0611618 . Bibcode:2007MNRAS.374..664C. doi: 10.1111/j.1365-2966.2006.11196.x . S2CID   119428437.
  9. ↑ Bernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities". Contributi Osservatorio Astronomico di Padova in Asiago. 239 (1): 1. Bibcode:1970CoAsi.239....1B.
  10. ↑ "HR 2530 -- Star in double system". SIMBAD. Centre de Données astronomiques de Strasbourg . Retrieved 2010-08-27.
  11. ↑ Perryman, M. A. C.; et al. (1997). "The Hipparcos Catalogue". Astronomy and Astrophysics. 323: L49–L52. Bibcode:1997A&A...323L..49P.
  12. ↑ "The Colour of Stars". Australia Telescope, Outreach and Education. Commonwealth Scientific and Industrial Research Organisation. December 21, 2004. Archived from the original on March 18, 2012. Retrieved 2012-01-16.
  13. ↑ National Center for Atmospheric Research (August 26, 2010). "Distant star's sound waves reveal cycle similar to the Sun's". PhysOrg.com . Retrieved 2010-08-27.
  14. ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv: 0806.2878 . Bibcode:2008MNRAS.389..869E. doi: 10.1111/j.1365-2966.2008.13596.x . S2CID   14878976.
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