[ The pair had an angular separation of 5.0 arcseconds as of 1994. This corresponds to a projected separation of around 128 AU.[4]]The primary component is an evolving G-type subgiant star with a stellar classification of G8 IV.[5] It is about 1.6 times the mass of the Sun and has 4 times the Sun's radius.[12] The star shines with 392[13] times the solar luminosity from its outer atmosphere at an effective temperature of 5,135 K.[12] Unusually for a star of this class, it shows a photometric variability of 0.04 in magnitude, which may be due to a previous mass transfer from the secondary companion, or else from an undiscovered third companion.[12]
The companion is about 7 magnitudes fainter than the primary and may be the source of the X-ray emission from this system. This emission has a luminosity of {{Val|504.4e27|u=erg s−1}}.[12]
References
1. ^1 {{citation | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | title=A catalogue of multiplicity among bright stellar systems | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=2 | pages=869–879 | date=September 2008 | doi=10.1111/j.1365-2966.2008.13596.x | bibcode=2008MNRAS.389..869E | arxiv=0806.2878 | postscript=. }}
2. ^1 2 {{citation | display-authors=1 | last=Torres | first=C. A. O. | last2=Quast | first2=G. R. | last3=Da Silva | first3=L. | last4=De La Reza | first4=R. | last5=Melo | first5=C. H. F. | last6=Sterzik | first6=M. | title=Search for associations containing young stars (SACY). I. Sample and searching method | journal=Astronomy and Astrophysics | volume=460 | issue=3 | date=December 2006 | pages=695–708 | doi=10.1051/0004-6361:20065602 | bibcode=2006A&A...460..695T | arxiv=astro-ph/0609258 | postscript=. }}
3. ^1 2 3 4 5 {{citation | last=Fuhrmann | first=K. | last2=Chini | first2=R. | title=Multiplicity among F-type Stars | journal=The Astrophysical Journal Supplement | volume=203 | issue=2 | pages=20 | id=30 | date=2012 | doi=10.1088/0067-0049/203/2/30 | bibcode=2012ApJS..203...30F | postscript=. }}
4. ^1 2 {{citation | display-authors=1 | last1=McDonald | first1=I. | last2=Zijlstra | first2=A. A. | last3=Boyer | first3=M. L. | title=Fundamental Parameters and Infrared Excesses of Hipparcos Stars | journal=Monthly Notices of the Royal Astronomical Society | volume=427 | issue=1 | pages=343–57 | date=2012 | bibcode=2012MNRAS.427..343M | arxiv=1208.2037 | doi = 10.1111/j.1365-2966.2012.21873.x | postscript=. }}
5. ^1 2 3 {{citation | display-authors=1 | last1=Poveda | first1=A. | last2=Herrera | first2=M. A. | last3=Allen | first3=C. | last4=Cordero | first4=G. | last5=Lavalley | first5=C. | title=Statistical studies of visual double and multiple stars. II. A catalogue of nearby wide binary and multiple systems | journal=Revista Mexicana de Astronomía y Astrofísica | volume=28 | issue=1 | pages=43–89 | date=April 1994 | bibcode=1994RMxAA..28...43P | postscript=. }} See pp. 58–59.
6. ^1 2 3 4 {{citation | last1=Mermilliod | first1=J.-C. | title=Compilation of Eggen's UBV data, transformed to UBV (unpublished) | journal=Catalogue of Eggen's UBV data | publisher=SIMBAD | date=1986 | bibcode=1986EgUBV........0M | postscript=. }}
7. ^1 {{cite simbad | title=* chi Eri -- Pre-main sequence Star | accessdate=2016-10-27 | postscript=. }}