[ Based upon an annual parallax shift of 43.37 mas as seen from Earth,[1] this star is located about 75 light years from the Sun. It is moving away from the Sun with a radial velocity of +18 km/s.[6]]There is disagreement in the literature as to the stellar classification of this star. Malaroda (1975) has it catalogued as F1 III, which would suggest it is an evolved F-type giant star.[2] Houk (1979) listed it as F3 IV/V, which appears to indicate a less evolved F-type star transitioning between the main sequence and subgiant star.[3] Gray et al. (2006) has it classed as F4 V, which would match an ordinary F-type main-sequence star.[4]
This star is a suspected astrometric binary.[13] The visible component has 1.55 times the mass of the Sun[ and 2.2[8] times the Sun's radius. At the age of around 1.4[9] billion years, it retains a relatively high rate of spin with a projected rotational velocity of 94 km/s.[10] It is radiating 11[7] times the Sun's luminosity from its photosphere at an effective temperature of 6,679 K.[9]]
Gamma Tucanae may (95% chance) have a distant co-moving companion – a magnitude 6.64 G-type main-sequence star of class G0 V designated HD 223913. This object has the same mass as the Sun and is separated from Gamma Tucanae by about {{Convert|3.5|pc|ly|abbr=on|order=flip}}.[14]
References
1. ^1 2 3 4 5 {{cite journal | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653 | year=2007 | last1=Van Leeuwen | first1=F. }} Vizier catalog entry
2. ^1 {{citation | title=Study of the F-type stars. I. MK spectral types | last1=Malaroda | first1=S. | postscript=. | journal=Astronomical Journal | volume=80 | pages=637–641 | date=August 1975 | doi=10.1086/111786 | bibcode=1975AJ.....80..637M }}
3. ^1 {{citation | last1=Houk | first1=Nancy | title=Michigan catalogue of two-dimensional spectral types for the HD stars | publication-place=Ann Arbor, Michigan | publisher=Department of Astronomy, University of Michigan | volume=1 | year=1979 | bibcode=1978mcts.book.....H | postscript=. }}
4. ^1 {{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=. }}
5. ^1 {{cite journal |bibcode=2002yCat.2237....0D |title=VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system |journal=CDS/ADC Collection of Electronic Catalogues |volume=2237 |author1=Ducati |first1=J. R. |year=2002 }}
6. ^1 {{Cite journal | doi=10.1134/S1063773706110065 | bibcode=2006AstL...32..759G| title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system| journal=Astronomy Letters| volume=32| issue=11| pages=759| year=2006| last1=Gontcharov| first1=G. A.|arxiv = 1606.08053 }}
7. ^1 2 3 {{cite journal | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015 | arxiv=1108.4971 | title=XHIP: An extended hipparcos compilation | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | last1=Anderson | first1=E. | last2=Francis | first2=Ch. }} Vizier catalog entry
8. ^1 {{cite journal | bibcode=1999A&A...352..555A | arxiv=astro-ph/9911002 | title=Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures | journal=Astronomy and Astrophysics | volume=352 | pages=555 | author1=Allende Prieto | first1=C. | last2=Lambert | first2=D. L. | year=1999 }} Vizier catalog entry
9. ^1 2 3 4 {{cite journal | bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146 | arxiv=1501.03154 | title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets | journal=The Astrophysical Journal | volume=804 | issue=2 | pages=146 | year=2015 | last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A. }} Vizier catalog entry
10. ^1 {{cite journal | bibcode=1995yCat.5050....0H | title=VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991) | journal=VizieR On-line Data Catalog: V/50. Originally published in: 1964BS....C......0H | volume=5050 | author1=Hoffleit | first1=D. | last2=Warren | first2=W. H. | year=1995 }}
11. ^{{cite web | url =http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Gamma+tuc&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id | title=Gamma Tucanae | work =SIMBAD Astronomical Database | publisher=Centre de Données astronomiques de Strasbourg | accessdate=20 October 2013 }}
12. ^{{cite journal | title=On Frederick de Houtman's Catalogue of Southern Stars, and the Origin of the Southern Constellations | last1=Knobel | first1=E. B. | journal=Monthly Notices of the Royal Astronomical Society | volume=77 | issue=5 | pages=414–32 [430] | bibcode=1917MNRAS..77..414K |year=1917 | doi=10.1093/mnras/77.5.414}}
13. ^{{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=. }}
14. ^{{citation | last1=Shaya | first1=Ed J. | last2=Olling | first2=Rob P. | title=Very Wide Binaries and Other Comoving Stellar Companions: A Bayesian Analysis of the Hipparcos Catalogue | journal=The Astrophysical Journal Supplement | volume=192 | issue=1 | page=2 |date=January 2011 | doi=10.1088/0067-0049/192/1/2 | bibcode=2011ApJS..192....2S |arxiv = 1007.0425 }}