| 词条 | Gamma2 Normae |
| 释义 |
| name = Gamma2 Normae}}{{Starbox observe | epoch = J2000.0 | equinox = J2000.0 (ICRS) | constell = Norma |ra= {{RA|16|19|50.42227}}[1] |dec= {{DEC|−50|09|19.8223}}[1] | appmag_v=4.02[1] }}{{Starbox character | type = | class = K0III[2] | b-v =+1.08[1] | u-b =+1.16[1] }}{{Starbox astrometry | radial_v = {{Val|−28.9|0.7}}[3] | prop_mo_ra = −159.71[1] | prop_mo_dec = −52.25[1] | parallax = 25.33 | p_error = 0.20 | parallax_footnote = [4] | absmag_v= 1.057[5] }}{{Starbox detail | source = | mass = 2.16[5] | radius = | luminosity = 51[6] | temperature = 4,699[5] | gravity = 2.80[5] | metal_fe = 0.23[5] | rotational_velocity = | age_gyr = }}{{Starbox catalog | names= {{odlist | B=γ2 Nor | CD=−49° 10536 | GJ=9554 | HD=146686 | HIP=80000 | HR=6072 | SAO=243643 | GC=12216 }}[7] }}{{Starbox reference | Simbad=HIP+80000 | ARICNS=02747 }}{{Starbox end}}Gamma2 Normae, Latinized from γ2 Nor, is the brightest star in the southern constellation of Norma. Its apparent magnitude is 4.02[1] – making it a faint star but visible to the naked eye. Based upon an annual parallax shift of 25.33 mas as seen from Earth,[4] this star is located roughly 129 light years from the Sun. It is moving closer to the Sun with a radial velocity of −29 km/s.[3] This is an evolved, yellow-hued giant of spectral type K0 III[2] around 2.16[5] times as massive as the Sun that has swollen to a diameter 10 times that of the Sun.[8] It is a red clump star on the horizontal branch, which indicates it is generating energy through helium fusion at its core. The star is radiating 51[6] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,699 K.[5] Gamma2 Normae is a close double, with a magnitude 10 companion. The pair has been previously identified as a binary star system,[27] but the second release of Gaia data showed the companion star to be much more distant. Another 16-magnitude star, with a temperature of {{val|5,972|u=K|fmt=commas}}, is listed 20" away with nearly the same parallax and proper motion as Gamma2 Normae.[9] γ1 Nor is a yellow supergiant located nearby on the celestial sphere, but is much further away from Earth and nearly a magnitude fainter. References1. ^1 2 3 {{citation | display-authors=1 | last1=Johnson | first1=H. L. | last2=Iriarte | first2=B. | last3=Mitchell | first3=R. I. | last4=Wisniewskj | first4=W. Z. | title=UBVRIJKL photometry of the bright stars | journal=Communications of the Lunar and Planetary Laboratory | volume=4 | issue=99 | pages=99 | year=1966 | bibcode=1966CoLPL...4...99J | postscript=. }} [10]2. ^1 {{citation | last1=Houk | first1=Nancy | title=Michigan catalogue of two-dimensional spectral types for the HD stars | volume=2 | publication-place=Ann Arbor | publisher=Dept. of Astronomy, University of Michigan | year=1978 | bibcode=1978mcts.book.....H | postscript=. }} 3. ^1 {{citation | last1=Gontcharov | first1=G. A. | title=Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system | journal=Astronomy Letters | volume=32| issue=11| pages=759–771| date=November 2006 | doi=10.1134/S1063773706110065 | bibcode=2006AstL...32..759G | arxiv=1606.08053 | postscript=. }} 4. ^1 2 3 4 5 {{cite journal | first=F. | last=van Leeuwen | title=Validation of the New Hipparcos Reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–64 | date=2007 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | arxiv=0708.1752}} 5. ^1 2 3 4 5 6 {{citation | postscript=. | display-authors=1 | last1=Liu | first1=Y. J. | last2=Zhao | first2=G. | last3=Shi | first3=J. R. | last4=Pietrzyński | first4=G. | last5=Gieren | first5=W. | title=The abundances of nearby red clump giants | journal=Monthly Notices of the Royal Astronomical Society | volume=382 | issue=2 | pages=553–66 | date=2007 | bibcode=2007MNRAS.382..553L | doi=10.1111/j.1365-2966.2007.11852.x }} 6. ^1 {{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=. }} 7. ^{{cite simbad|title=* gam02 Nor|accessdate=22 December 2012}} 8. ^{{cite web| first1=James B. | last1=Kaler | title=Gamma-2 Normae | work=Stars | publisher=University of Illinois | url=http://stars.astro.illinois.edu/sow/gamma2nor.html | accessdate=23 March 2015}} 9. ^{{cite DR2}} 10. ^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=. }} }}{{Stars of Norma}} 9 : K-type giants|Horizontal-branch stars|Norma (constellation)|Bayer objects|Durchmusterung objects|Gliese and GJ objects|Henry Draper Catalogue objects|Hipparcos objects|HR objects |
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