LL Pegasi

Last updated
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
Radius 1,074 [6]   R☉
Luminosity 10,900 [6]   L☉
Temperature 1,800 [6]   K
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. [7]

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. [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]

See also

Related Research Articles

<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">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">UU Aurigae</span> Star in the constellation of Auriga

UU Aurigae is a carbon star in the constellation Auriga. It is approximately 341 parsecs from Earth.

Theta<sup>1</sup> Orionis C Multiple star in the constellation Orion

Theta1 Orionis C is a member of the Trapezium open cluster that lies within the Orion Nebula. The star C is the most massive of the four bright stars at the heart of the cluster. It is an O class blue main sequence star with a B-type main sequence companion. Its high luminosity and large distance give it an apparent visible magnitude of 5.1.

<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">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">U Aquilae</span> Variable binary star system in the constellation Aquila

U Aquilae is a binary star system in the constellation Aquila, Located approximately 614 parsecs (2,000 ly) away from Earth.

<span class="mw-page-title-main">89 Herculis</span> Star in the constellation Hercules

89 Herculis is a binary star system located about 4,700 light years away from the Sun in the northern constellation of Hercules. It is visible to the naked eye as a faint, fifth magnitude star. The system is moving closer to the Earth with a heliocentric radial velocity of −28.5 km/s.

<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

U Camelopardalis is a semiregular variable star in the constellation Camelopardalis. Based on parallax measurements made by the Hipparcos spacecraft, it is located about 3,000 light-years away from the Earth. Its apparent visual magnitude is about 8, which is dim enough that it cannot be seen with the unaided eye.

<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">72 Pegasi</span> Binary star system in the constellation Pegasus

72 Pegasi is a binary star system in the northern constellation of Pegasus. It is visible to the naked eye as a faint, orange-hued point of light with a combined apparent visual magnitude of 4.97. The system is located approximately 550 light years away from the Sun, based on parallax, but is drifting closer with a radial velocity of −25 km/s.

<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">ZZ Boötis</span>

ZZ Boötis is a star system in the constellation Boötes. It varies from magnitude 6.79 to 7.44 over five days. Based on its parallax, measured by the Gaia spacecraft, it is about 350 light-years away.

EQ Pegasi is a nearby binary system of two red dwarfs. Both components are flare stars, with spectral types of M4Ve and M6Ve respectively, and a current separation between the components of 5.8 arcseconds. The system is at a distance of 20.4 light-years, and is 950 million years old. The primary star is orbited by one known exoplanet.

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

HDE 316285 is a blue supergiant star in the constellation Sagittarius. It is a candidate luminous blue variable and lies about 6,000 light years away in the direction of the galactic centre.

<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.

<span class="mw-page-title-main">SX Centauri</span> Supergiant variable star in the constellation Centaurus

SX Centauri is a variable star in the constellation Centaurus. An RV Tauri variable, its light curve alternates between deep and shallow minima, varying its apparent magnitude from 9.1 to 12.4. From the period-luminosity relationship, it is estimated to be around 1.6 kpc from Earth. Gaia Data Release 2 gives a parallax of 0.2175 mas, corresponding to distance of about 4,600 pc.

<span class="mw-page-title-main">R Fornacis</span> Variable star in the constellation Fornax

R Fornacis is a Mira variable and carbon star located in the constellation Fornax. It is around 1,800 light years away based on parallax measurements.

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 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.
  7. 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 .
  8. 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.
  9. ↑ 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.
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.