This image from the NASA/ESA Hubble Space Telescope shows a visible light view of the outer dust around the young star HD 100546. The position of the newly discovered protoplanet is marked with an orange spot. The inner part of this picture is dominated by artifacts from the brilliant central star, which has been digitally subtracted, and the black blobs are not real.
Epoch J2000.0 Equinox J2000.0
|Right ascension||11h 33m 25.441s|
|Declination||−70° 11′ 41.24″|
|Apparent magnitude (V)||6.698|
|Proper motion (μ)||RA: −38.93 ± 0.36 mas/yr
Dec.: 0.29 ± 0.38 mas/yr
|Parallax (π)||10.32 ± 0.43 mas|
|Distance||320 ± 10 ly
(97 ± 4 pc)
|Extrasolar planet||List of extrasolar planets||
|Right ascension||(α)||11h 33m 25.441s|
|Declination||(δ)||−70° 11′ 41.24″|
|Semimajor axis||(a)||6.5 AU|
HD 100546, also known as KR Muscae, is a star 320 LY from Earth. It is orbited by an approximately 20 MJ planet at 6.5 AU, 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. 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.
Possible birth of new planet
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.
HD 100546 b
Evidence for a planetary companion to HD 100546 was gathered using the UVES echelle spectrograph at the VLT in Chile. 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.
Coronagraphic optical observations with the Hubble Space Telescope  show complex spiral patterns in the circumstellar disk. The causes of these structures remain uncertain. The disk colors are similar to those derived for Kuiper Belt objects, suggesting that the same weathering processes are at work in HD 100546. The disk is fairly flat, consistent with an advanced evolutionary state.
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. The material is found at distances out to 17 AU away from the star and has a temperature of approximately 227 K.
- Ardila, D. R.; Golimowski, D. A.; Krist, J. E.; Clmapin, M.; Ford, H. C.; Illingworth, G. D. (2007). "Hubble Space Telescope Advanced Camera for Surveys Coronagraphic Observations of the Dust Surrounding HD 100546". Astrophysical Journal 665 (1): 512–534. arXiv:0704.1507. Bibcode:2007ApJ...665..512A. doi:10.1086/519296.
- "The Birth of a Giant Planet?". ESO. Retrieved 3 April 2013.
- "SIMBAD Object query: HD 100546".
- 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
- 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.
- 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.
- Mulders, Gijs D.; Paardekooper, Sijme-Jan; Pani´c, Olja; Dominik, Carsten et al. (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.
- Quanz, Sasch P.; Amara, Adam; Meyer, Michael P.; Kenworthy, Matthew P. et al. (2013). "A young protoplanet candidate embedded in the circumstellar disk of HD 100546" (PDF). Astrophysics Journal 766: L1–L6. arXiv:1302.7122. Bibcode:2013ApJ...766L...1Q. doi:10.1088/2041-8205/766/1/l1.
- "Is HD 100546 showing us the birth of a giant planet?". Science Codex. 2013-02-28. Retrieved 2013-03-01.
- Butler, R. P. et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal 646 (1): 505–522. arXiv:astro-ph/0607493. Bibcode:2006ApJ...646..505B. doi:10.1086/504701.
- Ecuvillon, A.; Israelian, G.; Pont, F.; Santos, N. et al. (August 2006). "Kinematics of planet-host stars and their relation to dynamical streams in the solar neighbourhood". Astronomy and Astrophysics 461 (171): 171–182. arXiv:astro-ph/0608669. Bibcode:2007A&A...461..171E. doi:10.1051/0004-6361:20065872.
- Jones, B.; Sleep, P.; Underwood, D. (June 2006). "Habitability of known exoplanetary systems based on measured stellar properties". The Astrophysical Journal 649 (1010): 1010–1019. arXiv:astro-ph/0603200. Bibcode:2006ApJ...649.1010J. doi:10.1086/506557.
- Mandell, Avi M.; Raymond, Sean N.; Sigurdsson, Steinn (May 2007). "Formation of Earth-like Planets During and After Giant Planet Migration". The Astrophysical Journal 660: 823–844. arXiv:astro-ph/0701048. Bibcode:2007ApJ...660..823M. doi:10.1086/512759.
- Marchi, S. (May 2007). "Extrasolar planet taxonomy: a new statistical approach". The Astrophysical Journal 666: 475–485. arXiv:0705.0910. Bibcode:2007ApJ...666..475M. doi:10.1086/519760.
- Hedrick, C. H.; Doering, R.; Lee, K.-G.; Sosey, M. et al. (January 2006). "The Circumstellar Dust Disk of HD 100546". American Astronomical Society 37 (4).
- Astronomy picture of the day - May 2, 2001