CH Cygni

{{Starbox begin

| name=CH Cygni

}}

{{Starbox image

| image=

{{Location mark

|image=Cygnus constellation map.svg|alt=|float=center|width=280

|label=|position=right

|mark=Red circle.svg|mark_width=10|mark_link=χ Cyg

|x=630|y=192

}}

|caption=Location of CH Cygni (circled)

}}

{{Starbox observe

| epoch=J2000

| ra={{RA|19|24|33.06773}}

| dec={{DEC|+50|14|29.1263}}

| appmag_v=5.60 – 8.49

| constell=Cygnus

}}

{{Starbox character

| class=M7IIIab + Be

| b-v=

| u-b=

| variable=Z And and SR

}}

{{Starbox astrometry

| radial_v=−59.74

| prop_mo_ra=−7.09

| prop_mo_dec= −59.74

| gal_lat=

| gal_lon=

| parallax=5.4642

| p_error=0.2172

| dist_pc=

| dist_ly=

| parallax_footnote=

| absmag_v=

}}

{{Starbox orbit

| reference=

| period={{val|15.58|0.13}}

| eccentricity={{val|0.122|0.024}}

| axis_unitless={{val|8.5|ul=AU}}

| inclination=84

| k1={{val|4.45|0.12}}

}}

{{Starbox detail

| source =

| component1= Red giant

| mass=2

| radius=280

| luminosity=5012

| temperature=3,100

| metal_fe=

| gravity=

| rotational_velocity=

| component2= White dwarf

| mass2=0.7

| radius2=

| luminosity2=0.25

| temperature2=

| metal_fe2=

| rotational_velocity2=

| age_gyr2=

}}

{{Starbox catalog

| names= HD 182917, BD+49°2999, HIP 95413, SAO 31632

}}

{{Starbox reference |

Simbad=CH+Cygni

}}

CH Cygni (CH Cyg / HIP 95413 / BD +49 2999) is a red giant, variable, symbiotic binary in the constellation Cygnus.

Properties

CH Cygni has a mass of {{solar mass|2}} and a radius of {{solar radius|280}}. Its white-dwarf companion has a mass of {{solar mass|0.75}}, and the orbital period of the two stars is 5689 days. CH Cygni is classified as M7IIIab + Be.

Observation history

File:CHCygLightCurve.png light curve for CH Cygni, adapted from Wallerstein et al. (2010)]]

The earliest observations of CH Cygni were made in 1890 by Pickering and Wendel using wedge photometer, and was classified as a M6III variable star in 1924. In 1963 strong H I emissions were observed, indicating CH Cygni was likely in a symbiotic relationship with a white dwarf. Similar emissions were observed in 1965, 1967, 1977, 1992, and 1998. The system was briefly thought to contain a third star but this was later disproved.

In 1984 bipolar jets were detected coming from CH Cygni, which were suspected to be due to accretion from its companion star. The luminosity of the system decreased significantly in 1986, likely owing to dust thrown out of the system by the jets or a concurrent helium flash. This dust had dissipated by 2002, with subsequent luminosities returning to pre-1985 levels.

References

{{reflist|refs=

{{cite journal |last1=Burmeister |first1=M. |last2=Leedjärv |first2=L. |title=Spectroscopy of the symbiotic binary CH Cygni from 1996 to 2007 |journal=Astronomy & Astrophysics |date=9 July 2009 |volume=504 |issue=1 |pages=171–180 |doi=10.1051/0004-6361/200911686 |arxiv=0907.2017 |bibcode=2009A&A...504..171B |s2cid=2498584 }}

{{cite journal |last1=Wallerstein |first1=George |last2=Munari |first2=U. |last3=Siviero |first3=A. |last4=Dallaporta |first4=S. |last5=Dalmeri |first5=I. |title=The Spectrum and Light Curve of CH Cygni during its Recent Broad Minimum |journal=Publications of the Astronomical Society of the Pacific |date=January 2010 |volume=122 |issue=887 |pages=12–16 |doi=10.1086/648563 |bibcode=2010PASP..122...12W |s2cid=120765815 |doi-access=free }}

{{cite journal |last1=Famaey |first1=B. |last2=Pourbaix |first2=D. |last3=Frankowski |first3=A. |last4=Van Eck |first4=S. |last5=Mayor |first5=M. |last6=Udry |first6=S. |last7=Jorissen |first7=A. |title=Spectroscopic binaries among Hipparcos M giants |journal=Astronomy & Astrophysics |date=18 February 2009 |volume=498 |issue=2 |pages=627–640 |doi=10.1051/0004-6361/200810698 |arxiv=0901.0934 |bibcode=2009A&A...498..627F |s2cid=18739721 }}

{{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 |last1=Hinkle |first1=Kenneth H. |last2=Fekel |first2=Francis C. |last3=Johnson |first3=Diana S. |last4=Scharlach |first4=Werner W. G. |title=The triple symbiotic system CH Cygni |journal=The Astronomical Journal |date=March 1993 |volume=105 |pages=1074 |doi=10.1086/116494|bibcode=1993AJ....105.1074H }}

{{cite journal|doi=10.1088/0004-637X/692/2/1360|bibcode=2009ApJ...692.1360H|arxiv=0811.0631|title=Infrared Spectroscopy of Symbiotic Stars. Vii. Binary Orbit and Long Secondary Period Variability of Ch Cygni|journal=The Astrophysical Journal|volume=692|issue=2|pages=1360|year=2009|last1=Hinkle|first1=Kenneth H|last2=Fekel|first2=Francis C|last3=Joyce|first3=Richard R|s2cid=14500048}}

{{cite journal |last1=Mikołajewski |first1=M. |last2=Mikołajewska |first2=J. |last3=Khudiakova |first3=T.N. |title=A long-period symbiotic binary CH Cygni. I - A hundred years' history of variability |journal=Astronomy and Astrophysics |date=August 1990 |volume=235 |issue=1–2 |pages=219–233 |issn=0004-6361 |bibcode=1990A&A...235..219M}}

{{cite journal|bibcode=2011ARep...55...31S|doi=10.1134/S1063772911010070|title=Search for and study of hot circumstellar dust envelopes|journal=Astronomy Reports|volume=55|pages=31–81|year=2011|last1=Shenavrin|first1=V. I|last2=Taranova|first2=O. G|last3=Nadzhip|first3=A. E|issue=1|s2cid=122700080}}

{{cite journal |last1=van Leeuwen |first1=F. |title=Validation of the new Hipparcos reduction |journal=Astronomy & Astrophysics |date=13 August 2007 |volume=474 |issue=2 |pages=653–664 |doi=10.1051/0004-6361:20078357|arxiv=0708.1752 |bibcode=2007A&A...474..653V |s2cid=18759600 }}

}}

Category:Cygnus (constellation)

Category:M-type giants

182917

095413

Category:Durchmusterung objects

Category:Z Andromedae variables

Cygni, CH

Category:Semiregular variable stars