LL Pegasi

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LL Pegasi
Celestial spiral with a twist.jpg
LL Pegasi is continuously losing gaseous material as it evolves into a planetary nebula. [1]
Observation data
Epoch J2000.0        Equinox J2000.0 (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]
Astrometry
Distance 1,300 [3]   pc
Details
A
Mass 3.5 [6]   M
Radius 1,074 [7]   R
Luminosity 10,900 [7]   L
Temperature 1,800 [7]   K
B
Mass 3.1 [6]   M
Other designations
LL Pegasi, IRAS 23166+1655, 2MASS J23191260+1711331, RAFGL 3068
Database references
SIMBAD data

LL Pegasi (AFGL 3068) is a Mira variable star surrounded by a pinwheel-shaped nebula, IRAS 23166+1655, thought to be a preplanetary nebula. It is a binary system that includes an extreme carbon star. The pair is hidden by the dust cloud ejected from the carbon star and is only visible in infrared light. [8]

Contents

Variability

A near-infrared (L- band) light curve for LL Pegasi, plotted from data published by Le Bertre (1992) LLPegLightCurve.png
A near-infrared (L- band) light curve for LL Pegasi, plotted from data published by Le Bertre (1992)

LL Pegasi is obscured at visual wavelengths, but is strongly variable in brightness at infrared wavelengths. [9] It is classified as a Mira variable and has a period of about 696 days. [10]

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. [8]

See also

Related Research Articles

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IM Pegasi is a variable binary star system approximately 329 light-years away in the constellation of Pegasus. With an apparent magnitude of 5.7, it is visible to the naked eye. Increased public awareness of it is due to its use as the guide star for the Gravity Probe B general relativity experiment. It was chosen for this purpose because its microwave radio emissions are observable with a large radio telescope network on the ground in such a manner that its precise position can be related by interferometry to distant quasars.

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

W Sagittarii is a multiple star system star in the constellation Sagittarius, and a Cepheid variable star.

<span class="mw-page-title-main">X Sagittarii</span> Variable star and possible binary star system in the constellation Sagittarius

X Sagittarii is a variable star and candidate binary star system in the southern constellation of Sagittarius, near the western constellation boundary with Ophiuchus. It has a yellow-white hue and is visible to the naked eye with an apparent visual magnitude that fluctuates around 4.54. The star is located at a distance of approximately 950 light years from the Sun based on parallax, and is drifting closer with a radial velocity of −10 km/s. The star has an absolute magnitude of around −2.85.

<span class="mw-page-title-main">U Antliae</span> Carbon star in the constellation Antlia

U Antliae is a variable star in the constellation Antlia. It is a carbon star surrounded by two thin shells of dust.

<span class="mw-page-title-main">26 Andromedae</span> Star in the constellation Andromeda

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<span class="mw-page-title-main">Tau Pegasi</span> Star in the constellation Pegasus

Tau Pegasi, formally named Salm, is a magnitude 4.6 star 162 light years away in the constellation of Pegasus. With about twice the mass of the Sun and thirty times as luminous, it is a δ Scuti variable star with its brightness changing by a few hundredths of a magnitude over about an hour.

<span class="mw-page-title-main">CS Camelopardalis</span> Binary star in the constellation Camelopardalis

CS Camelopardalis is a binary star in reflection nebula VdB 14, in the constellation Camelopardalis.

<span class="mw-page-title-main">R Aquarii</span> Star in the constellation of Aquarius

R Aquarii is a variable star in the constellation Aquarius.

<span class="mw-page-title-main">II Pegasi</span> Star in the constellation Pegasus

II Pegasi is a binary star system in the constellation of Pegasus with an apparent magnitude of 7.4 and a distance of 130 light-years. It is a very active RS Canum Venaticorum variable, a close binary system with active starspots.

<span class="mw-page-title-main">HR 4049</span> Protoplanetary nebula in the constellation Antlia

HR 4049, also known as HD 89353 and AG Antliae, is a binary post-asymptotic-giant-branch (post-AGB) star in the constellation Antlia. A very metal-poor star, it is surrounded by a thick unique circumbinary disk enriched in several molecules. With an apparent magnitude of about 5.5, the star can readily be seen under ideal conditions. It is located approximately 1,700 parsecs (5,500 ly) distant.

<span class="mw-page-title-main">HD 110432</span> Star in the constellation Crux

HD 110432 is a Be star in the south-east of Crux, behind the center of the southern hemisphere's dark Coalsack Nebula. It has a stellar classification of B1IVe, which means it is a subgiant star of class B that displays emission lines in its spectrum. This is a variable star of the Gamma Cassiopeiae type, indicating it is a shell star with a circumstellar disk of gas about the equator, and has the variable star designation BZ Crucis. It is not known to be a member of a binary system, although it is probably a member of the open cluster NGC 4609. This star is moderately luminous in the X-ray band, with a variable energy emission of 1032–33 erg s−1 in the range 0.2−12 keV. The X-ray emission may be caused by magnetic activity, or possibly by accretion onto a white dwarf companion.

<span class="mw-page-title-main">U Camelopardalis</span> Star in the constellation Camelopardalis

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<span class="mw-page-title-main">9 Pegasi</span> Star in the constellation Pegasus

9 Pegasi is a supergiant star in the constellation Pegasus. Its apparent magnitude is 4.35.

<span class="mw-page-title-main">Nu Pegasi</span> Star in the constellation Pegasus

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<span class="mw-page-title-main">Theta Muscae</span> Star in the constellation Musca

Theta Muscae is a multiple star system in the southern constellation Musca, containing a Wolf-Rayet star and two massive companions. With an apparent magnitude of 5.5, it is the second-brightest Wolf–Rayet star in the sky, although much of the visual brightness comes from the massive companions and it is not one of the closest of its type.

<span class="mw-page-title-main">AG Pegasi</span> Star in the constellation Pegasus

AG Pegasi is a symbiotic binary star in the constellation Pegasus. It is a close binary composed of a red giant and white dwarf, estimated to be around 2.5 and 0.6 times the mass of the Sun respectively. It is classified as a symbiotic nova; it has undergone one extremely slow nova outburst and a smaller outburst.

<span class="mw-page-title-main">HD 316285</span> Star in the constellation Sagittarius

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<span class="mw-page-title-main">HD 87643</span> Binary star system in the constellation Carina

HD 87643 is a B[e] class binary star embedded in a reflection nebula.

<span class="mw-page-title-main">HD 65750</span> Star in the constellation Carina

HD 65750, also known as V341 Carinae is a bright red giant star in the constellation Carina. It is surrounded by a prominent reflection nebula, known as IC 2220, nicknamed the Toby Jug Nebula.

Psi<sup>2</sup> Orionis Spectroscopic binary system in the constellation of Orion

Psi2 Orionis a binary star system in the equatorial constellation of Orion. It has an apparent visual magnitude of 4.6, indicating that it is visible to the naked eye. Based upon an annual parallax shift of 2.87 mass, it is roughly 1,100 light years distant from the Sun.

References

  1. "Celestial spiral with a twist". eso.org. European Southern Observatory. Retrieved 13 February 2022.
  2. 1 2 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. 1 2 Lombaert, R.; De Vries, B. L.; De Koter, A.; Decin, L.; Min, M.; Smolders, K.; Mutschke, H.; Waters, L. B. F. M. (2012). "Observational evidence for composite grains in an AGB outflow. MgS in the extreme carbon star LL Pegasi". Astronomy & Astrophysics. 544: L18. arXiv: 1207.1606 . Bibcode:2012A&A...544L..18L. doi:10.1051/0004-6361/201219782. S2CID   119022145.
  4. Groenewegen, M. A. T.; De Jong, T.; Gaballe, T. R. (1994). "The 3 micrometer spectra of candidate carbon stars". Astronomy and Astrophysics. 287: 163. Bibcode:1994A&A...287..163G.
  5. Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  6. 1 2 Kim, Hyosun; Taam, Ronald E. (2012-10-17). "A NEW METHOD OF DETERMINING THE CHARACTERISTICS OF EVOLVED BINARY SYSTEMS REVEALED IN THE OBSERVED CIRCUMSTELLAR PATTERNS: APPLICATION TO AFGL 3068". The Astrophysical Journal. 759 (1): L22. arXiv: 1209.6360 . doi:10.1088/2041-8205/759/1/l22. ISSN   2041-8205.
  7. 1 2 3 Massalkhi, S.; Agúndez, M.; Cernicharo, J. (August 2019). "Study of CS, SiO, and SiS abundances in carbon star envelopes: Assessing their role as gas-phase precursors of dust". Astronomy & Astrophysics. 628: A62. arXiv: 1906.09461 . Bibcode:2019A&A...628A..62M. doi:10.1051/0004-6361/201935069. ISSN   0004-6361. PMC   6739229 . PMID   31511746.
  8. 1 2 Morris, Mark; Sahai, Raghvendra; Matthews, Keith; Cheng, Judy; Lu, Jessica; Claussen, Mark; Sánchez-Contreras, Carmen (2006). "A Binary-Induced Pinwheel Outflow from the Extreme Carbon Star, AFGL 3068". Planetary Nebulae in Our Galaxy and Beyond. 234: 469. Bibcode:2006IAUS..234..469M. doi: 10.1017/S1743921306003784 .
  9. 1 2 Le Bertre, T. (1992). "Carbon-star lightcurves in the 1-20 micron range". Astronomy and Astrophysics Supplement Series. 94: 377. Bibcode:1992A&AS...94..377L.
  10. Whitelock, Patricia A.; Feast, Michael W.; Marang, Freddy; Groenewegen, M. A. T. (2006). "Near-infrared photometry of carbon stars". Monthly Notices of the Royal Astronomical Society. 369 (2): 751–782. arXiv: astro-ph/0603504 . Bibcode:2006MNRAS.369..751W. doi: 10.1111/j.1365-2966.2006.10322.x . S2CID   14453496.