}}{{Starbox reference
| Simbad = HD+40409
}}{{Starbox end}}HD 40409 is a suspected astrometric binary[13] star system in the southern constellation of Dorado. It is a faint system but visible to the naked eye with an apparent visual magnitude of 4.65.[3] Based upon an annual parallax shift of {{Val|36.96|ul=mas}},[1] it is located 88 light years away from the Sun. It is moving further away with a heliocentric radial velocity of +25 km/s.[3] The system has a relatively high proper motion, traversing the celestial sphere at the rate of {{Val|0.57|ul=arcseconds}} per year along a position angle of 14.51°.[17]The visible component is an evolved K-type giant star, based upon a stellar classification of K2 III assigned by Gray et al. (2006).[4] In contrast, Keenan and McNeil (1989) gave it a somewhat less evolved classification of K2 III–IV.[19] It is about eight billion years old with 12% more mass than the Sun, and has expanded to 4.8 times the Sun's radius. The star is radiating 11 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,858 K.[11]
References
1. ^1 2 3 4 5 6 {{cite DR2}}
2. ^1 2 {{citation | title=The Pan-Pacific Planet Search. V. Fundamental Parameters for 164 Evolved Stars | last1=Wittenmyer | first1=Robert A. | last2=Liu | first2=Fan | last3=Wang | first3=Liang | last4=Casagrande | first4=Luca | last5=Johnson | first5=John Asher | last6=Tinney | first6=C. G. | journal=The Astronomical Journal | postscript=. | volume=152 | issue=1 | id=19 | pages=15 | date=July 2016 | doi=10.3847/0004-6256/152/1/19 | bibcode=2016AJ....152...19W |arxiv = 1605.00323 }}
3. ^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=. }}
4. ^1 2 3 4 5 6 {{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 | postscript=. }}
5. ^1 2 {{citation | display-authors=1 | last1=Gray | first1=R. O. | last2=Corbally | first2=C. J. | last3=Garrison | first3=R. F. | last4=McFadden | first4=M. T. | last5=Bubar | first5=E. J. | last6=McGahee | first6=C. E. | last7=O'Donoghue | first7=A. A. | last8=Knox | first8=E. R. | title=Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample | journal=The Astronomical Journal | volume=132 | issue=1 | pages=161–170 | date=July 2006 | doi=10.1086/504637 | bibcode=2006AJ....132..161G | arxiv=astro-ph/0603770 | postscript=. }}
6. ^1 {{citation | display-authors=1 | last1=Bakos | first1=Gáspár Á. | last2=Sahu | first2=Kailash C. | last3=Németh | first3=Péter | title=Revised Coordinates and Proper Motions of the Stars in the Luyten Half-Second Catalog | journal=The Astrophysical Journal Supplement Series | volume=141 | issue=1 | pages=187–193 | date=July 2002 | doi=10.1086/340115 | bibcode=2002ApJS..141..187B | arxiv=astro-ph/0202164 | postscript=. }}
7. ^1 {{citation | title=The Perkins catalog of revised MK types for the cooler stars | journal=Astrophysical Journal Supplement Series | last1=Keenan | first1=Philip C. | last2=McNeil | first2=Raymond C. | volume=71 | pages=245 | year=1989 | postscript=. | bibcode=1989ApJS...71..245K | doi=10.1086/191373 }}