LL Pegasi

{{Starbox image

| image = 250px

| caption = LL Pegasi is continuously losing gaseous material as it evolves into a planetary nebula.

}}

{{Starbox observe

| epoch = J2000.0

| equinox = J2000.0 (ICRS)

| constell = Pegasus

| ra = {{RA|23|19|12.607}}

| dec = {{DEC|+17|11|33.13}}

| appmag_v=

}}

{{Starbox character

| type = Asymptotic giant branch

| class = C

| b-v =

| r-i =

| variable = Mira

}}

{{Starbox astrometry

| radial_v =

| prop_mo_ra =

| prop_mo_dec =

| parallax =

| p_error =

| parallax_footnote =

| dist_pc = 1,300

| absmag_v=

}}

{{Starbox detail

| component1 = A

| mass = 3.5

| radius = {{solar radius calculator|type=LT|10900|1800|decimals=-2}}{{Cite journal|last1=Massalkhi|first1=S.|last2=Agúndez|first2=M.|last3=Cernicharo|first3=J.|date=August 2019|title=Study of CS, SiO, and SiS abundances in carbon star envelopes: Assessing their role as gas-phase precursors of dust|arxiv=1906.09461|journal=Astronomy & Astrophysics|volume=628|pages=A62|doi=10.1051/0004-6361/201935069|pmid=31511746 |pmc=6739229 |bibcode=2019A&A...628A..62M |issn=0004-6361}}{{efn|name=radius}}

| luminosity = 10,900

| temperature = 1,800

| component2 = B

| mass2 = 3.1

}}

{{Starbox catalog

| names = {{odlist|V=LL Pegasi|2MASS=J23191260+1711331|IRAS=23166+1655}}, RAFGL 3068

}}

{{Starbox reference

| Simbad=LL+Pegasi

}}

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.

Variability

File:LLPegLightCurve.png) 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. It is classified as a Mira variable and has a period of about 696 days.

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.

Gallery

3D view of LL Pegasi.webm|Observed structure surrounding the binary star system.

Pre-planetary nebula, IRAS 23166+1655.jpg|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.

Notes

{{notelist|notes=

{{efn | name=radius | Applying the Stefan–Boltzmann law with a nominal solar effective temperature of 5,772 K:

: $\sqrt{\biggl(\frac{5,772}{1,800}\biggr)^4 \cdot {10,900}} = 1,100\ R_\odot$ .}}

}}

References

{{Reflist|refs=

{{cite web |title=Celestial spiral with a twist |url=https://www.eso.org/public/images/potw1710a/ |website=eso.org |publisher=European Southern Observatory |access-date=13 February 2022}}

{{cite journal |bibcode=2003yCat.2246....0C |title=VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) |journal=CDS/ADC Collection of Electronic Catalogues |pages=II/246 |volume=2246 |last1=Cutri |first1=Roc M. |last2=Skrutskie |first2=Michael F. |last3=Van Dyk |first3=Schuyler D. |last4=Beichman |first4=Charles A. |last5=Carpenter |first5=John M. |last6=Chester |first6=Thomas |last7=Cambresy |first7=Laurent |last8=Evans |first8=Tracey E. |last9=Fowler |first9=John W. |last10=Gizis |first10=John E. |last11=Howard |first11=Elizabeth V. |last12=Huchra |first12=John P. |last13=Jarrett |first13=Thomas H. |last14=Kopan |first14=Eugene L. |last15=Kirkpatrick |first15=J. Davy |last16=Light |first16=Robert M. |last17=Marsh |first17=Kenneth A. |last18=McCallon |first18=Howard L. |last19=Schneider |first19=Stephen E. |last20=Stiening |first20=Rae |last21=Sykes |first21=Matthew J. |last22=Weinberg |first22=Martin D. |last23=Wheaton |first23=William A. |last24=Wheelock |first24=Sherry L. |last25=Zacarias |first25=N. |year=2003 |url=http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=II/246 }}

{{Cite journal |last1=Kim |first1=Hyosun |last2=Taam |first2=Ronald E. |title=A New Method of Determining the Characteristics of Evolved Binary Systems Revealed in the Observed Circumstellar Patterns: Application to Afgl 3068 |date=2012-10-17 |journal=The Astrophysical Journal |volume=759 |issue=1 |pages=L22 |doi=10.1088/2041-8205/759/1/l22 |issn=2041-8205|arxiv=1209.6360 }}

{{cite journal|bibcode=2012A&A...544L..18L|title=Observational evidence for composite grains in an AGB outflow. MgS in the extreme carbon star LL Pegasi|journal=Astronomy & Astrophysics|volume=544|pages=L18|last1=Lombaert|first1=R.|last2=De Vries|first2=B. L.|last3=De Koter|first3=A.|last4=Decin|first4=L.|last5=Min|first5=M.|last6=Smolders|first6=K.|last7=Mutschke|first7=H.|last8=Waters|first8=L. B. F. M.|year=2012|doi=10.1051/0004-6361/201219782|arxiv = 1207.1606 |s2cid=119022145}}

{{cite journal|bibcode=2009yCat....102025S|title=VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)|journal=VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S|volume=1|display-authors=etal|last1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}

{{cite journal|bibcode=2006IAUS..234..469M|title=A Binary-Induced Pinwheel Outflow from the Extreme Carbon Star, AFGL 3068|journal=Planetary Nebulae in Our Galaxy and Beyond|volume=234|pages=469|last1=Morris|first1=Mark|last2=Sahai|first2=Raghvendra|last3=Matthews|first3=Keith|last4=Cheng|first4=Judy|last5=Lu|first5=Jessica|last6=Claussen|first6=Mark|last7=Sánchez-Contreras|first7=Carmen|year=2006|doi=10.1017/S1743921306003784 |doi-access=free}}

{{cite journal|bibcode=2006MNRAS.369..751W|arxiv=astro-ph/0603504|title=Near-infrared photometry of carbon stars|journal=Monthly Notices of the Royal Astronomical Society|volume=369|issue=2|pages=751–782|last1=Whitelock|first1=Patricia A.|last2=Feast|first2=Michael W.|last3=Marang|first3=Freddy|last4=Groenewegen|first4=M. A. T.|year=2006|doi=10.1111/j.1365-2966.2006.10322.x|doi-access=free |s2cid=14453496}}

{{cite journal|bibcode=1992A&AS...94..377L|title=Carbon-star lightcurves in the 1-20 micron range|journal=Astronomy and Astrophysics Supplement Series|volume=94|pages=377|last1=Le Bertre|first1=T.|year=1992}}

{{cite journal|bibcode=1994A&A...287..163G|title=The 3 micrometer spectra of candidate carbon stars|journal=Astronomy and Astrophysics|volume=287|pages=163|last1=Groenewegen|first1=M. A. T.|last2=De Jong|first2=T.|last3=Gaballe|first3=T. R.|year=1994}}

}}

External links

[https://www.eso.org/public/videos/potw1710a/ 3D view of LL Pegasi]
[https://www.eso.org/public/images/potw1710a/ Celestial spiral with a twist]
[http://www.spacetelescope.org/images/potw1020a/ An Extraordinary Celestial Spiral]
[https://web.archive.org/web/20100909151403/http://cosmiclog.msnbc.msn.com/_news/2010/09/07/5062638-celestial-spiral-goes-viral Celestial spiral goes viral]
[http://news.discovery.com/space/hubble-spots-ghostly-space-spiral.html Hubble Spots Ghostly Space Spiral — discovery.com]
[http://antwrp.gsfc.nasa.gov/apod/ap100914.html An Extraordinary Spiral from LL Pegasi], APOD

Category:Protoplanetary nebulae

Category:IRAS catalogue objects

Pegasi, LL

Category:Pegasus (constellation)

Category:Carbon stars

Category:Mira variables

J23191260+1711331

Category:TIC objects