LL Pegasi

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LL Pegasi

LL Pegasi is continuously losing gaseous material as it evolves into a planetary nebula.[1]
Observation data
ICRS
)
Constellation Pegasus
Right ascension 23h 19m 12.607s[2]
Declination +17° 11′ 33.13″[2]
Characteristics
Evolutionary stage Asymptotic giant branch[3]
Spectral type C[4]
Variable type Mira[5]
Distance
1,300[3] pc
Details
Radius1,074[6] R☉
Luminosity10,900[6] L☉
Temperature1,800[6] K
LL Pegasi, IRAS 23166+1655, 2MASS
J23191260+1711331, RAFGL 3068
Database references
SIMBADdata

LL Pegasi (AFGL 3068) is a

dust cloud ejected from the carbon star and is only visible in infrared light.[7]

Variability

A near-infrared (L- band) light curve for LL Pegasi, plotted from data published by Le Bertre (1992)[8]

LL Pegasi is obscured at visual wavelengths, but is strongly variable in brightness at infrared wavelengths.[8] It is classified as a Mira variable and has a period of about 696 days.[9]

Nebula

The nebula displays an unusual Archimedean spiral shape. The shape is thought to be formed through the interaction between the stellar companion and the carbon star, as has been seen in other binary systems, although not with such a precise geometric form. The distance between the spiral arms and their rate of expansion is consistent with estimates of the pair's 810 year orbital period based on their apparent angular separation.[7]

Gallery

  • Observed structure surrounding the binary star system.
  • Hubble Space Telescope image of IRAS 23166+1655, taken in the near-infrared. The bright object to the right is a star much closer to Earth. It was used as a guide star for adaptive optics corrections that allowed the Keck II telescope to resolve the LL Pegasi binary pair.
    Keck II
    telescope to resolve the LL Pegasi binary pair.

See also

References

  1. ^ "Celestial spiral with a twist". eso.org. European Southern Observatory. Retrieved 13 February 2022.
  2. ^
    Bibcode:2003yCat.2246....0C
    .
  3. ^
    S2CID 119022145
    .
  4. Bibcode:1994A&A...287..163G
    .
  5. Bibcode:2009yCat....102025S
    .
  6. ^
    PMID 31511746
    .
  7. ^
    doi:10.1017/S1743921306003784
    .
  8. ^
    Bibcode:1992A&AS...94..377L
    .
  9. S2CID 14453496
    .

External links
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