AFGL 2298

Last updated
AFGL 2298
AFGL2298LightCurve.png
A near-infrared (J band) light curve for AFGL 2298, adapted from Clark et al. (2009) [1]
Observation data
Epoch J2000        Equinox J2000
Constellation Aquila
Right ascension 19h 00m 10.89s [2]
Declination +03° 45′ 47.1″ [2]
Characteristics
Spectral type B8I, [3] B:I:[e], [4] B0-0.5I [5]
Apparent magnitude  (J)12.164 [2]
Apparent magnitude  (H)8.918 [2]
Apparent magnitude  (K)6.91 [6]
Variable type LBV [4]
Astrometry
Distance 30,000±10,000  ly
(10,000±3,000 [4]   pc)
Absolute bolometric
magnitude  (Mbol)		−11.25 [1]
Details
Radius 158 - 385 [1]   R☉
Luminosity 1,300,000 - 2,000,000 [1]   L☉
Temperature 11,000 - 15,500 [1] or 26,000 [5]   K
Other designations
V1672 Aql, RAFGL 2298, IRAS 18576+0341, 2MASS J19001089+0345471 [7]
Database references
SIMBAD data

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 23,000 and 42,000 light years (7,000 to 13,000 parsecs) away from the Earth. [4] 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. [7]

AFGL 2298 was discovered during the US Air Force Geophysical Laboratory (AFGL) survey, a rocket based infrared sky survey conducted at Hanscom Air Force Base, whose results were published in 1975. [8]

AFGL 2298 has an absolute bolometric magnitude of −11.25, [1] 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. [1] Its status as an LBV was confirmed in 2003. [4]

Like most extremely massive stars, AFGL 2298 is undergoing mass loss. [5] For example, in 2005 it was estimated to be losing 3.7×10−5 solar masses each year, [5] although the rate of mass loss itself varies frequently and dramatically. [1] 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. [9] The nebula was found to be fairly circular, and the properties of the dust appeared to be constant throughout the entire nebula. [9]

Properties of AFGL 2298 over time [1]
Effective temperature  (K)Mass loss rate (M☉/yr) Bolometric luminosity  (L☉)
June 200111,7004.5×10−51.5×106
August 200210,9001.2×10−41.3×106
June 200610,3005.2×10−52.0×106
May 200710,9004×10−51.5×106

See also

Related Research Articles

<span class="mw-page-title-main">Pistol Star</span> Hypergiant star in Sagittarius

The Pistol Star is an extremely luminous blue hypergiant star, one of the most luminous and massive known stars in the Milky Way. It is one of many massive young stars in the Quintuplet cluster in the Galactic Center region. The star owes its name to the shape of the Pistol Nebula, which it illuminates. It is located approximately 25,000 light-years from Earth in the direction of Sagittarius. The star has a large mass comparable to V4998 Sagittarii and a luminosity 3.3 million times that of the Sun (L☉). It would be visible to the naked eye as a 4th-magnitude star if it were not for the interstellar dust near the Center of the Milky Way that absorbs almost all of its visible light.

<span class="mw-page-title-main">S Doradus</span> Star in the Large Magellanic Cloud

S Doradus is one of the brightest stars in the Large Magellanic Cloud (LMC), a satellite galaxy of the Milky Way, located roughly 160,000 light-years away. The star is a luminous blue variable, and one of the most luminous stars known, having a luminosity varying widely above and below 1,000,000 times the luminosity of the Sun, although it is too far away to be seen with the naked eye.

<span class="mw-page-title-main">Luminous blue variable</span> Type of star that is luminous, blue, and variable in brightness

Luminous blue variables (LBVs) are rare, massive and evolved stars that show unpredictable and sometimes dramatic variations in their spectra and brightness. They are also known as S Doradus variables after S Doradus, one of the brightest stars of the Large Magellanic Cloud.

<span class="mw-page-title-main">P Cygni</span> Variable star in the constellation Cygnus

P Cygni is a variable star in the constellation Cygnus. The designation "P" was originally assigned by Johann Bayer in Uranometria as a nova. Located about 5,300 light-years from Earth, it is a hypergiant luminous blue variable (LBV) star of spectral type B1-2 Ia-0ep that is one of the most luminous stars in the Milky Way.

<span class="mw-page-title-main">AG Carinae</span> Luminous variable star in the constellation Carina

AG Carinae is a star in the constellation Carina. It is classified as a luminous blue variable (LBV) and is one of the most luminous stars in the Milky Way. The great distance and intervening dust mean that the star is not usually visible to the naked eye; its apparent brightness varies erratically between magnitude 5.7 and 9.0.

<span class="mw-page-title-main">Cygnus OB2-12</span> Blue hypergiant star

Cygnus OB2 #12 is an extremely luminous blue hypergiant with an absolute bolometric magnitude of −10.9, among the most luminous stars known in the galaxy. This makes the star nearly two million times more luminous than the Sun, although estimates were even higher when the star was first discovered. It is now known to be a binary, with the companion approximately a tenth as bright. A very approximate initial estimate of the orbit gives the total system mass as 120 M☉ and the period as 30 years.

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

HR Carinae is a luminous blue variable star located in the constellation Carina. It is surrounded by a vast nebula of ejected nuclear-processed material because this star has a multiple shell expanding atmosphere. This star is among the most luminous stars in the Milky Way. It has very broad emission wings on the Balmer lines, reminiscent from the broad lines observed in the spectra of O and Wolf–Rayet stars. A distance of 5 kpc and a bolometric magnitude of −9.4 put HR Car among the most luminous stars of the galaxy.

<span class="mw-page-title-main">WR 102ka</span> Star in the constellation Sagittarius

WR 102ka, also known as the Peony star, is a slash star that is one of several candidates for the most luminous-known star in the Milky Way.

<span class="mw-page-title-main">Hypergiant</span> Rare star with tremendous luminosity and high rates of mass loss by stellar winds

A hypergiant (luminosity class 0 or Ia+) is a very rare type of star that has an extremely high luminosity, mass, size and mass loss because of its extreme stellar winds. The term hypergiant is defined as luminosity class 0 (zero) in the MKK system. However, this is rarely seen in literature or in published spectral classifications, except for specific well-defined groups such as the yellow hypergiants, RSG (red supergiants), or blue B(e) supergiants with emission spectra. More commonly, hypergiants are classed as Ia-0 or Ia+, but red supergiants are rarely assigned these spectral classifications. Astronomers are interested in these stars because they relate to understanding stellar evolution, especially star formation, stability, and their expected demise as supernovae. Notable examples of hypergiants include the Pistol Star, a blue hypergiant located close to the Galactic Center and one of the most luminous stars known; Rho Cassiopeiae, a yellow hypergiant that is one of the brightest to the naked eye; and Mu Cephei (Herschel's "Garnet Star"), one of the largest and brightest stars known.

Zeta<sup>1</sup> Scorpii Star in the constellation Scorpius.

Zeta1 Scorpii is a B-type hypergiant star in the constellation of Scorpius. It has an apparent visual magnitude which varies between 4.66 and 4.86. It is a member of the Scorpius OB1 association, and potentially of the open star cluster NGC 6231, also known as the "Northern jewel box" cluster. Around 36 times as massive as the Sun, it is also one of the most luminous stars known in the Galaxy, with an estimated bolometric luminosity of around 850,000 times that of the Sun and a radius 103 times that of the Sun.

<span class="mw-page-title-main">Wray 17-96</span> Star in Scorpius

Wray 17-96 is a very luminous star in the Scorpius constellation, about 20,000 light-years (7 kpc) away. It is a suspected luminous blue variable (LBV), although it has not shown the characteristic spectral variations.

<span class="mw-page-title-main">HD 168625</span> Star in the constellation Sagittarius

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.

<span class="mw-page-title-main">HD 168607</span> Star in the constellation Sagittarius

HD 168607 is a blue hypergiant and luminous blue variable (LBV) star located in the constellation of Sagittarius, easy to see with amateur telescopes. It forms a pair with HD 168625, also a blue hypergiant and possible luminous blue variable, that can be seen at the south-east of M17, the Omega Nebula.

<span class="mw-page-title-main">HD 160529</span> Luminous blue variable star in the constellation Scorpius

HD 160529 is a luminous blue variable (LBV) star located in the constellation of Scorpius. With an apparent magnitude of around +6.8 cannot be seen with the naked eye except under very favourable conditions, but it is easy to see with binoculars or amateur telescopes.

BD+40°4210 is a hot luminous giant star located in the constellation Cygnus. It is a member of the Cygnus OB2 association and a candidate luminous blue variable.

<span class="mw-page-title-main">WR 31a</span> Wolf Rayet star in the constellation Carina

WR 31a, commonly referred to as Hen 3-519, is a Wolf–Rayet (WR) star in the southern constellation of Carina that is surrounded by an expanding Wolf–Rayet nebula. It is not a classical old stripped-envelope WR star, but a young massive star which still has some hydrogen left in its atmosphere.

<span class="mw-page-title-main">Romano's Star</span> Star in the constellation Taurus

Romano's Star is a luminous blue variable star located in the Messier 33 galaxy in the constellation of Triangulum.

<span class="mw-page-title-main">R71 (star)</span> Star in the Large Magellanic Cloud

R71 is a star in the Large Magellanic Cloud (LMC) in the constellation Mensa. It is classified as a luminous blue variable and is one of the most luminous stars in the LMC. It lies three arc-minutes southwest of the naked-eye star β Mensae.

<span class="mw-page-title-main">AF Andromedae</span> Luminous blue variable star in the constellation Andromeda

AF Andromedae is a luminous blue variable (LBV), a type of variable star. The star is one of the most luminous variables in M31, the Andromeda Galaxy.

References

  1. 1 2 3 4 5 6 7 8 9 Clark, J. S.; et al. (2009). "Bolometric luminosity variations in the luminous blue variable AFGL2298". Astronomy and Astrophysics. 507 (3): 1555–1565. arXiv: 0909.4160 . Bibcode:2009A&A...507.1555C. doi:10.1051/0004-6361/200912358. S2CID   119187994.
  2. 1 2 3 4 Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E.; Fowler, John W.; Gizis, John E.; Howard, Elizabeth V.; Huchra, John P.; Jarrett, Thomas H.; Kopan, Eugene L.; Kirkpatrick, J. Davy; Light, Robert M.; Marsh, Kenneth A.; McCallon, Howard L.; Schneider, Stephen E.; Stiening, Rae; Sykes, Matthew J.; Weinberg, Martin D.; Wheaton, William A.; Wheelock, Sherry L.; Zacarias, N. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
  3. ↑ Ramírez Alegría, S.; Herrero, A.; Rübke, K.; Marín-Franch, A.; García, M.; Borissova, J. (2018). "Identifying two groups of massive stars aligned in the l 38° Galactic direction". Astronomy and Astrophysics. 614: A116. arXiv: 1801.08683 . Bibcode:2018A&A...614A.116R. doi:10.1051/0004-6361/201731720. S2CID   119427413.
  4. 1 2 3 4 5 Clark, J. S.; et al. (2003). "Confirmation of the Luminous Blue Variable nature of AFGL 2298". Astronomy and Astrophysics. 403 (2): 653–658. Bibcode:2003A&A...403..653C. doi: 10.1051/0004-6361:20030389 .
  5. 1 2 3 4 Umana, G.; Buemi, C. S.; Trigilio, C.; Leto, P. (2005). "Current day mass loss rate for Luminous Blue Variable IRAS 18576+0341". Astronomy and Astrophysics. 437 (1): L1–L5. Bibcode:2005A&A...437L...1U. doi: 10.1051/0004-6361:200500126 .
  6. ↑ Kazarovets, E. V. (2006). "The 78th Name-List of Variable Stars". Information Bulletin on Variable Stars. 5721: 1. Bibcode:2006IBVS.5721....1K.
  7. 1 2 "AFGL 2298". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 26 January 2017.
  8. ↑ Walker, R. G.; Price, S. D. (July 14, 1975). AFCRL Infrared Sky Survey (PDF). United States Air Force. Retrieved 22 November 2024.
  9. 1 2 Buemi, C. S.; et al. (2010). "VISIR/VLT and VLA Joint Imaging Analysis of the Circumstellar Nebula Around IRAS 18576+0341". The Astrophysical Journal. 721 (2): 1404–1411. arXiv: 1008.0997 . Bibcode:2010ApJ...721.1404B. doi:10.1088/0004-637X/721/2/1404. S2CID   119281049.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.