HD 100546

From Wikipedia, the free encyclopedia
Jump to: navigation, search
HD 100546
Observation data
Epoch J2000.0[1]      Equinox J2000.0[1]
Constellation Musca
Right ascension 11h 33m 25.441s[2]
Declination −70° 11′ 41.24″[2]
Apparent magnitude (V) 6.698[1]
Spectral type B9Vne[1]
Age >106[3] years
Proper motion (μ) RA: −38.93 ± 0.36[2] mas/yr
Dec.: 0.29 ± 0.38[2] mas/yr
Parallax (π) 10.32 ± 0.43[2] mas
Distance 320 ± 10 ly
(97 ± 4 pc)
Other designations
V* KR Mus, SAO 251457, CD−69 893, HIP 56379, [1]
HD 100546 b
Extrasolar planet List of extrasolar planets|
Parent star
Star HD 100546
Right ascension (α) 11h 33m 25.441s[2]
Declination (δ) −70° 11′ 41.24″[2]
Spectral type B9Vne[1]
Physical characteristics
Mass (m) ~20[4] MJ
Orbital elements
Semimajor axis (a) 6.5[4] AU
Artist's impression of a gas giant planet forming in the disc around the young star HD 100546.[5]

HD 100546, also known as KR Muscae, is a star 320 LY from Earth.[2] It is orbited by an approximately 20 Mj planet at 6.5 AU,[4] although further examination of the disk profile indicate it might be a more massive object such as a brown dwarf or more than one planet.[6] 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.[7]

Estimated to be around 10 million years old, it is at the upper age limit of the class of stars it belongs to—Herbig Ae/Be stars, and also the nearest example to our Solar System.[3]

Possible birth of new planet[edit]

In 2013, researchers reported that they had found what seems to be a planet in the process of being formed, embedded in the star's large disc of gas and dust. If confirmed, it would represent the first opportunity to study the early stages of planet formation observationally.[8]

HD 100546 b[edit]

Evidence for a planetary companion to HD 100546 was gathered using the UVES echelle spectrograph at the VLT in Chile.[4] This confirms other data indicating a planetary companion. The planet's size puts it near the border between a giant planet and a brown dwarf.[4]

Protoplanetary material[edit]

Spectroscopic analysis of mid-IR data taken from OSCIR on the 4 m Blanco Telescope at Cerro Tololo Inter-American Observatory indicates the presence of a small particles (10–18 μm) containing silicates.[3] The material is found at distances out to 17 AU away from the star and has a temperature of approximately 227 K.[3]


  1. ^ a b c d e "SIMBAD Object query: HD 100546". 
  2. ^ a b c d e f g h van Leeuwen, F. (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. Vizier catalog entry
  3. ^ a b c d Grady, C. A. et al. "The Disk and Environment of the Herbig Be Star HD 100546". The Astronomical Journal 122 (6): 3396–3406. Bibcode:2001AJ....122.3396G. doi:10.1086/324447. 
  4. ^ a b c d e Acke, B.; van der Ancker; M. (November 2005). "Resolving the disk rotation of HD 97048 and HD 100546 in the [O I] 6300A line: evidence for a giant planet orbiting HD 100546". Astronomy and Astrophysics 449 (267): 267. arXiv:astro-ph/0512562. Bibcode:2006A&A...449..267A. doi:10.1051/0004-6361:20054330. 
  5. ^ "The Birth of a Giant Planet?". ESO. Retrieved 3 April 2013. 
  6. ^ Mulders, Gijs D.; Paardekooper, Sijme-Jan; Pani´c, Olja; Dominik, Carsten; van Boekel, Roy; Ratzka, Thorsten (2013). "Planet or Brown Dwarf? Inferring the Companion Mass in HD 100546 from the Wall Shape using Mid-Infrared Interferometry". Astronomy & Astrophysics 557A (A68): 10. arXiv:1306.4264. Bibcode:2013A&A...557A..68M. doi:10.1051/0004-6361/201220930. 
  7. ^ Quanz, Sasch P.; Amara, Adam; Meyer, Michael P.; Kenworthy, Matthew P.; Kasper, Markus; Girard, Julien H. (2013). "A young protoplanet candidate embedded in the circumstellar disk of HD 100546". Astrophysics Journal 766: L1–L6. arXiv:1302.7122. Bibcode:2013ApJ...766L...1Q. doi:10.1088/2041-8205/766/1/l1. 
  8. ^ "Is HD 100546 showing us the birth of a giant planet?". Science Codex. 2013-02-28. Retrieved 2013-03-01. 

Further reading[edit]

External links[edit]

Coordinates: Sky map 11h 33m 25.4408s, −70° 11′ 41.239″