47 Capricorni

{{about|c² Capricorni|other stars with this Bayer designation|c Capricorni}}

{{Starbox image

| image = 250px

| caption = A light curve for AG Capricorni, plotted from Hipparcos data

}}

{{starbox observe

| epoch = J2000

| constell = Capricornus

| ra = {{RA|21|46|16.26887}}

| dec = {{DEC|−09|16|33.3799}}

| appmag_v = 6.00 {{nowrap|(5.90 - 6.14)}}

}}

{{starbox character

| type = giant

| class = M2III

| b-v = {{Val|1.629|0.010}}

| variable = SRb

}}

{{starbox astrometry

| radial_v = {{Val|+19.80|0.89}}

| prop_mo_ra = +18.731

| prop_mo_dec = +8.387

| parallax = 2.7933

| p_error = 0.2052

| parallax_footnote =

| absmag_v = −1.76

}}

{{Starbox detail

| component1 =

| mass =

| radius = {{Val|102|11|10}}

| temperature = {{Val|3784|188|186|fmt=commas}}

| luminosity = {{Val|1940|162|fmt=commas}}

| rotational_velocity =

| gravity =

| metal_fe =

| age_myr =

}}

{{starbox catalog

| names = {{odlist | V=AG Cap | B=c² Cap | F=47 Cap | BD=−09°5833 | HD=207005 | HIP=107487 | HR=8318 | SAO=145648 }}

}}

{{Starbox reference

| Simbad=47+Cap

}}

47 Capricorni is a variable star located around 1,170 light years from the Sun in the southern constellation Capricornus, near the northern border with Aquarius. It has the variable star designation of AG Capricorni and a Bayer designation of c² Capricorni; 47 Capricorni is the Flamsteed designation. This object is visible to the naked eye as a dim, red-hued point of light with an apparent visual magnitude that varies between 5.90 and 6.14. The star is receding from the Earth with a heliocentric radial velocity of +20 km/s.

In 1963, Alan William James Cousins announced that 47 Capricorni is a variable star. It was given its variable star designation in 1973.

This is an aging red giant star with a stellar classification of M2III. It is a semiregular variable star of subtype SRb with a period of 30.592 days and a maximum brightness of 5.9 magnitude. With the supply of hydrogen at its core exhausted, the star has expanded to around 102 times the Sun's radius. It is radiating 1,940 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,784 K.

References

{{reflist|refs=

{{citation

| title=XHIP: An extended hipparcos compilation

| last1=Anderson | first1=E. | last2=Francis | first2=Ch.

| journal=Astronomy Letters

| volume=38 | issue=5 | pages=331 | year=2012

| bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015

| arxiv=1108.4971 | s2cid=119257644 | postscript=. }}

{{cite journal

| last1=Kukarkin | first1=B. V. | last2=Kholopov | first2=P. N.

| last3=Kukarkina | first3=N. P. | last4=Perova | first4=N. B.

| title=59th Name-List of Variable Stars | journal=Information Bulletin on Variable Stars

| date=October 1973 | volume=834 | bibcode=1973IBVS..834....1K

| url=https://ibvs.konkoly.hu/pub/ibvs/0801/0834.pdf | access-date=8 December 2024}}

{{cite journal

| last1=Cousins | first1=A. W. J. | title=Photometric Data for Stars in the Equatorial Zone (Third List)

| journal=Monthly Notes of the Astron. Soc. Southern Africa | date=1963 | volume=22 | page=12

| bibcode=1963MNSSA..22...12C |url=https://articles.adsabs.harvard.edu/pdf/1963MNSSA..22...12C

| access-date=8 December 2024}}

{{cite web |title=Hipparcos Tools Interactive Data Access |url=https://www.cosmos.esa.int/web/hipparcos/interactive-data-access |website=Hipparcos |publisher=ESA |access-date=8 December 2021}}

{{cite web

| title=HD 207005

| url=http://vizier.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=IV/27A/catalog&recno=3684

| work=HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index

| first1=N. D. | last1=Kostjuk | year=2002

| publisher=Institute of Astronomy of Russian Academy of Sciences; CDS }} [http://cdsarc.u-strasbg.fr/viz-bin/Cat?cat=IV%2F27A&target=readme IV/27A]

{{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. | display-authors=1

| title=Spectroscopic binaries among Hipparcos M giants,. I. Data, orbits, and intrinsic variations