| 词条 | AFGL 2298 | ||||||||||||||||||||
| 释义 |
|name=AFGL 2298}}{{Starbox observe |constell=Aquila |epoch=J2000 | ra = {{RA|19|00|10.89}}[1] | dec = {{DEC|+03|45|47.1}}[1] |appmag_v= }}{{Starbox character |appmag_1_passband=J |appmag_1=12.164[1] |appmag_2_passband=H |appmag_2=8.918[1] |appmag_3_passband=K |appmag_3=6.91[2] |class=B:I:[e][3] B0-0.5I[4] |variable=LBV[3] }}{{Starbox astrometry |dist_ly={{val|30000|10000|fmt=commas}} |dist_pc={{val|10000|3000|fmt=commas}}[3] |absmag_bol=-11.25[5] }}{{Starbox detail |radius=158 - 385[5] |temperature={{nobreak|11,000 - 15,500[5]}} or 26,000[4] |luminosity=1,300,000 - 2,000,000[5] }}{{Starbox catalog |names=V1672 Aql, RAFGL 2298, IRAS 18576+0341, 2MASS J19001089+0345471[6] }}{{Starbox reference |Simbad=RAFGL+2298}}{{Starbox end}}AFGL 2298, also known as IRAS 18576+0341, is a luminous blue variable star (LBV) located in the constellation Aquila, very close to the galactic plane. Its distance is not well known; it may be anywhere between {{val|23000|fmt=commas}} and {{val|42000|fmt=commas}} light years (7,000 to 13,000 parsecs) away from the Earth.[3] Despite being extremely luminous, it is extremely reddened by interstellar extinction, so its apparent magnitude is brighter for longer-wavelength passbands; in fact, in visual wavelengths it is completely undetectable.[6] AFGL 2298 has an absolute bolometric magnitude of −11.25,[5] making it one of the most luminous stars known. Indeed, many of the hottest and most luminous stars known are luminous blue variables and other early-type stars. However, like all LBVs, AFGL 2298 is highly variable and the bolometric magnitude refers to its peak luminosity.[5] Its status as an LBV was confirmed in 2003.[3] Like most extremely massive stars, AFGL 2298 is undergoing mass loss.[4] For example, in 2005 it was estimated to be losing {{val|3.7e-5}} solar masses each year,[4] although the rate of mass loss itself varies frequently and dramatically.[5] The stellar mass is currently being ejected as a nebula around the star (similar to AG Carinae), which was imaged by the Very Large Telescope in 2010.[7] The nebula was found to be fairly circular, and the properties of the dust appeared to be constant throughout the entire nebula.[7]
See also
References1. ^1 2 3 {{cite journal|title=2MASS All-Sky Catalog of Point Sources|date=2003|journal=VizieR On-line Data Catalog|author1=Cutri, R. M.|bibcode=2003yCat.2246....0C}} {{Stars of Aquila}}2. ^{{cite journal|title=The 78th Name-List of Variable Stars|author1=Kazarovets, E. V.|journal=Information Bulletin on Variable Stars|date=2006|bibcode=2006IBVS.5721....1K}} 3. ^1 2 3 4 {{cite journal|title=Confirmation of the Luminous Blue Variable nature of AFGL 2298|author1=Clark, J. S.|display-authors=etal|date=2003|journal=Astronomy and Astrophysics|volume=403|pages=653–658|bibcode=2003A&A...403..653C|doi=10.1051/0004-6361:20030389}} 4. ^1 2 3 {{cite journal|title=Current day mass loss rate for Luminous Blue Variable IRAS 18576+0341|author1=Umana, G.|author2=Buemi, C. S.|author3=Trigilio, C.|author4=Leto, P.|journal=Astronomy and Astrophysics|volume=437|issue=1|pages=L1–L5|date=2005|bibcode=2005A&A...437L...1U|doi=10.1051/0004-6361:200500126}} 5. ^1 2 3 4 5 6 7 {{cite journal|title=Bolometric luminosity variations in the luminous blue variable AFGL2298|author1=Clark, J. S.|display-authors=etal|journal=Astronomy and Astrophysics|volume=507|issue=3|pages=1555–1565|bibcode=2009A&A...507.1555C|doi=10.1051/0004-6361/200912358|arxiv=0909.4160}} 6. ^1 {{cite simbad|title=AFGL 2298|accessdate=26 January 2017}} 7. ^1 {{cite journal|title=VISIR/VLT and VLA Joint Imaging Analysis of the Circumstellar Nebula Around IRAS 18576+0341|author1=Buemi, C. S.|display-authors=etal|date=2010|journal=The Astrophysical Journal|volume=721|issue=2|pages=1404–1411|bibcode=2010ApJ...721.1404B|doi=10.1088/0004-637X/721/2/1404|arxiv=1008.0997}} 7 : Aquila (constellation)|B-type supergiants|Luminous blue variables|Objects with variable star designations|IRAS catalogue objects|Emission-line stars|2MASS objects |
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