| 词条 | Eta Cancri |
| 释义 |
| name = Eta Cancri }}{{Starbox observe | epoch = J2000 | constell = Cancer | ra = {{RA|08|32|42.49600}}[1] | dec = {{DEC|20|26|28.1865}}[1] | appmag_v = 5.34[2] }}{{Starbox character | class = K3 III[2] | b-v = +1.25[2] | u-b = +1.40[2] }}{{Starbox astrometry | radial_v = +22.46[3] | prop_mo_ra = −46.33[1] | prop_mo_dec = −44.31[1] | parallax = 10.93 | p_error = 0.40 | parallax_footnote = [1] | absmag_v = +0.44[4] }}{{Starbox detail | source = | mass = 1.51[5] | radius = 17[6] | luminosity = 87[5] | temperature = {{Val|4415|57|fmt=commas}}[5] | gravity = 2.1[6] | metal_fe = {{Val|0.07|0.21}}[4] | rotational_velocity = 2.7[6] | age_gyr = 3.92[5] }}{{Starbox catalog | names= {{odlist | B=η Cnc | F=33 Cnc | BD=+20° 2109 | FK5=321 | HD=72292 | HIP=41909 | HR=3366 | SAO=80243 | CCDM=| GC=11687 }}[7] }}{{Starbox reference | Simbad = eta+Cancri }}{{Starbox end}}Eta Cancri, Latinized from η Cancri, is a single,[8] orange-hued star in the zodiac constellation of Cancer. It is a faint star but visible to the naked eye with an apparent visual magnitude of 5.34.[2] The annual parallax shift of 10.93[1] mas as seen from Earth yields a distance estimate of 155 light years from the Sun. It is moving further away with a radial velocity of +22 km/s.[3] A stellar classification of K3 III[2] for Eta Cancri indicates that, at the estimated age of 3.9 billion years old,[5] it has left the main sequence and become an evolved giant star. The spectrum shows unusually strong absorption lines of cyanogen.[2] It has 1.5[5] times the mass of the Sun and has expanded to 17[6] times the Sun's radius. The star is radiating 87[5] times the Sun's luminosity from its photosphere at an effective temperature of around 4,415 K.[5] In Chinese astronomy, Ghost ({{zh|c=鬼宿|p=Guǐ Xiù}}) refers to an asterism consisting of Theta Cancri, Eta Cancri, Gamma Cancri and Delta Cancri.[9] Eta Cancri itself is the second star of Ghost ({{zh|c=鬼宿二|p=Guǐ Xiù èr}}), following the designation from its determinative star (θ Cnc) from east to west. References1. ^1 2 3 4 5 {{cite journal | title=Validation of the new Hipparcos reduction | url=http://www.aanda.org/articles/aa/full/2007/41/aa8357-07/aa8357-07.html | last1=van Leeuwen | first1=F. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | date=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 }} Vizier catalog entry {{Stars of Cancer}}2. ^1 2 3 4 5 6 {{cite journal | title=A photometric investigation of strong-cyanogen stars | last1=McClure | first1=R. D. | journal=Astronomical Journal | volume=75 | pages=41–52 | date=February 1970 | doi=10.1086/110938 | bibcode=1970AJ.....75...41M }} 3. ^1 {{citation | display-authors=1 | last1=Famaey | first1=B. | last2=Jorissen | first2=A. | last3=Luri | first3=X. | last4=Mayor | first4=M. | last5=Udry | first5=S. | last6=Dejonghe | first6=H. | last7=Turon | first7=C. | title=Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters | journal=Astronomy and Astrophysics | volume=430 | issue=1 | pages=165–186 |date=January 2005 | doi=10.1051/0004-6361:20041272 | bibcode=2005A&A...430..165F | arxiv=astro-ph/0409579 }} 4. ^1 {{citation | last1=Luck | first1=R. Earle | last2=Heiter | first2=Ulrike | title=Giants in the Local Region | journal=The Astronomical Journal | volume=133 | issue=6 | pages=2464–2486 | date=June 2007 | doi=10.1086/513194 | bibcode=2007AJ....133.2464L }} 5. ^1 2 3 4 5 6 7 {{citation | title=Abundances in the Local Region. I. G and K Giants | last1=Luck | first1=R. Earle | journal=The Astronomical Journal | volume=150 | issue=3 | id=88 | pages=23 | date=September 2015 | doi=10.1088/0004-6256/150/3/88 | bibcode=2015AJ....150...88L | arxiv=1507.01466 | postscript=. }} 6. ^1 2 3 {{citation | display-authors=1 | last1=Massarotti | first1=Alessandro | last2=Latham | first2=David W. | last3=Stefanik | first3=Robert P. | last4=Fogel | first4=Jeffrey | title=Rotational and radial velocities for a sample of 761 HIPPARCOS giants and the role of binarity | journal=The Astronomical Journal | volume=135 | issue=1 | pages=209–231 | date=January 2008 | doi=10.1088/0004-6256/135/1/209 | bibcode=2008AJ....135..209M }} 7. ^{{cite simbad | title=* eta Cnc | accessdate=2015-10-07 }} 8. ^{{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 | postscript=. |arxiv = 0806.2878 }} 9. ^{{cite book |author=陳久金 |script-title=中國星座神話 |title=Zhōngguó Xīngzuò Shénhuà |trans-title=Chinese Constellation Mythology |url=https://books.google.com/books?id=0Vex0rYzdu8C&pg=394 |year=2005 |publisher=台灣古籍出版有限公司 |isbn=978-986-7332-25-7 |page=394}} 8 : K-type giants|Cancer (constellation)|Bayer objects|Durchmusterung objects|Flamsteed objects|Henry Draper Catalogue objects|Hipparcos objects|HR objects |
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