IRC −10414

Source: Wikipedia, the free encyclopedia.
IRC −10414
Observation data
Epoch J2000      Equinox J2000
Constellation Scutum
Right ascension 18h 23m 17.90s[1]
Declination −13° 42′ 47.3″[1]
Apparent magnitude (V) 12.0[2]
Characteristics
Evolutionary stage Red supergiant[3]
Spectral type M7 I–M8[4]
Variable type SR[5]
Distance
2,000[3] pc
Details
Myr
Other designations
IRAS 18204-1344, IRC −10414, RAFGL 2139
Database references
SIMBADdata

IRC −10414 (RAFGL 2139) is a

runaway star in the constellation Scutum, a rare case of a red supergiant with a bow shock
.

Observations

Although IRC −10414 is an unobtrusive 12th magnitude star visually, early infrared observations quickly noted it as a bright source. Its position close to the galactic plane marked it as a potentially luminous object.[7] Observations then detected OH emission from the star, again indicating a potentially luminous cool supergiant.[8] Dusty circumstellar material was found around the star and it was assumed to be a highly evolved asymptotic giant branch (AGB) star. On the basis of this assumption, it was expected to be at about 700 parsecs from the sun.[9]

There were suspicions that IRC −10414 might be a true

VLBI measurements of SiO masers around IRC −10414 gave a distance around 2,000 parsecs and confirmed the red supergiant nature.[3]

Description

IRC −10414 has a

Wolf-Rayet star WR 114.[1]

Its distance is not very well known, but it is estimated to be of the order of 2

Eagle Nebula, and the Omega Nebula (the three sharing a similar distance to the Sun, of around 2 kiloparsecs too);[1] the studies of the water masers that surround it suggest a higher distance, up to around 3 kiloparsecs.[3] However, the birthplace of this star is not clear and its kinematics and age show its unlikely it had formed in any of the previous three star-forming regions mentioned.[1]

Assuming the distance given above and a surface temperature of 3,300

mas or a distance around 1 kpc gives the star a much lower luminosity of 30,200–39,400 L☉ with a corresponding radius of 597 R☉.[4]

Variability

A visual band light curve for IRC −10414, plotted from ASAS data[11]

IRC −10414 has been reported as a likely variable with a period of 768 days and an amplitude of over a magnitude.[12] Observations of a long series of All Sky Automated Survey observations again showed variability with an amplitude over a magnitude, but with a period of 2,726 days. The variability is unlikely to be regular and the most likely classification is given as semiregular.[5] It is not yet listed in the General Catalogue of Variable Stars.[13]

WR 114

Main article: WR 114

WR 114 (HD 169010) is a

light years-) is also similar.[14]

The actual distance between the two stars is unclear. The projected separation corresponds to a separation of 0.43 parsecs at the expected distance. If it is as close as that then the strong stellar wind of the former would impede the formation of the bow shock by IRC −10414. It has been suggested both stars formed part of a dissolved

triple star system moving more or less together. However the space motion of WR 114 are very poorly known so this cannot be confirmed.[1]

References

  1. ^
    S2CID 118416927
    .
  2. doi:10.1086/111833
    .
  3. ^
    doi:10.1093/pasj/60.5.1057
    .
  4. ^
    S2CID 148571616
    .
  5. ^
    S2CID 88519222
    .
  6. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR
    .
  7. doi:10.1086/111471
    .
  8. doi:10.1086/112020
    .
  9. doi:10.1086/167499
    .
  10. Bibcode:1984A&A...138..194U
    .
  11. ^ "ASAS All Star Catalogue". The All Sky Automated Survey. Retrieved 8 December 2021.
  12. Bibcode:2005AcA....55...97P
    .
  13. Bibcode:2009yCat....102025S
    .
  14. S2CID 119182468
    .
Retrieved from "https://en.wikipedia.org/w/index.php?title=IRC_−10414&oldid=1188080962"