To install click the Add extension button. That's it.

The source code for the WIKI 2 extension is being checked by specialists of the Mozilla Foundation, Google, and Apple. You could also do it yourself at any point in time.

How to transfigure the Wikipedia

Would you like Wikipedia to always look as professional and up-to-date? We have created a browser extension. It will enhance any encyclopedic page you visit with the magic of the WIKI 2 technology.

Try it — you can delete it anytime.

Install in 5 seconds
4,5
Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
I use WIKI 2 every day and almost forgot how the original Wikipedia looks like.
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
What we do. Every page goes through several hundred of perfecting techniques; in live mode. Quite the same Wikipedia. Just better.
Great Wikipedia has got greater.
.
Leo
Newton
Brights
Milds

HD 204018

From Wikipedia, the free encyclopedia

HD 204018
location of HD 204018 (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Microscopium
A
Right ascension 21h 27m 01.62303s[1]
Declination −42° 32′ 52.5560″[1]
Apparent magnitude (V) 5.58±0.01[2]
B
Right ascension 21h 27m 01.75500s[3]
Declination −42° 32′ 55.0458″[3]
Apparent magnitude (V) 8.09±0.01[2]
Characteristics
A
Evolutionary stage subgiant[4]
Spectral type kA4 hF0 V mF6[5]
U−B color index +0.15[6]
B−V color index +0.39[6]
B
Spectral type F8 V[7]
U−B color index +0.06[7]
B−V color index +0.55[7]
Astrometry
Radial velocity (Rv)18.3±2.8[8] km/s
A
Proper motion (μ) RA: −48.257 mas/yr[1]
Dec.: +13.160 mas/yr[1]
Parallax (π)18.489 ± 0.0498 mas[1]
Distance176.4 ± 0.5 ly
(54.1 ± 0.1 pc)
Absolute magnitude (MV)+1.74[9]
B
Proper motion (μ) RA: −53.002 mas/yr[3]
Dec.: +15.410 mas/yr[3]
Parallax (π)18.5325 ± 0.0349 mas[3]
Distance176.0 ± 0.3 ly
(54.0 ± 0.1 pc)
Absolute magnitude (MV)+4.00[7]
Details
A
Mass1.65±0.11[10] M☉
Radius2.55±0.13[11] R☉
Luminosity15±1.2[12] L☉
Surface gravity (log g)3.86±0.08[13] cgs
Temperature6,778[14] K
Rotational velocity (v sin i)85[15] km/s
Age1.36±0.19[1] Gyr
B
Mass1.02[16] M☉
Radius1.09±0.21[17] R☉
Surface gravity (log g)4.29[16] cgs
Temperature6,235±115[18] K
Metallicity [Fe/H]−0.11[19] dex
Age3.46[19] Gyr
Other designations
69 G. Microscopii[20], CD−43°14539, CPD−43°9451, GC 30021, HD 204018, HIP 105913, HR 8202, SAO 230692, WDS J21270-4233AB[21]
Database references
SIMBADThe system
A
B

HD 204018, also designated as HR 8202, is a visual binary located in the southern constellation Microscopium. The primary has an apparent magnitude of 5.58,[2] making it faintly visible to the naked eye under ideal conditions. The companion has an apparent magnitude of 8.09.[2] The system is located relatively close at a distance of 176 light years based on Gaia DR3 parallax measurements[1][3] but is receding with a heliocentric radial velocity of 18.3 km/s.[8] At its current distance, HD 204018's combined brightness is diminished by 0.13 magnitudes due to interstellar dust.[22]

HD 204018A is an Am star with a stellar classification of kA4hF0 VmF6,[5] indicating that it has the calcium K-line of an A4 star, the hydrogen lines of a F0 main-sequence star and the metallic lines of a F6 star. It has 1.65 times the mass of the Sun[10] and 2.55 times the Sun's radius.[11] It radiates 15 times the luminosity of the Sun[12] from its photosphere at an effective temperature of 6,778 K,[14] giving it a yellowish-white hue. At an age of 1.5 billion years, HD 2014018A is estimated to be on the subgiant branch.[4] An alternate model places it on the main sequence at an age of 1,35 billion years.[1] The object spins at a moderate speed with a projected rotational velocity of 85 km/s.[15]

The companion is an F8 main sequence star[7] located 2+1⁄2" away along a position angle of 151°.[23] It has an angular diameter of 0.186±0.035 arcseconds,[18] which yields a radius of 1.09 R☉ at its estimated distance.[17] It has 102% times the mass of the Sun[16] and an effective temperature of 6,235 K.[18] HD 204018B is estimated to be 3.46 billion years old and is slightly metal deficient.[19]

There is a magnitude 12 co-moving companion located 295.3" away from the system along a position angle of 75°.[23] It is a red dwarf with an estimated spectral class of K6 and any orbit would take over a million years.[24]

References

  1. ^ a b c d e f g Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ a b c d Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (March 2002). "The Tycho double star catalogue". Astronomy & Astrophysics. 384 (1): 180–189. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822. eISSN 1432-0746. ISSN 0004-6361.
  3. ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  4. ^ a b Corbally, C. J. (December 1984). "Close visual binaries. III - Parameters and evolutionary status". The Astronomical Journal. 89: 1887. Bibcode:1984AJ.....89.1887C. doi:10.1086/113700. ISSN 0004-6256.
  5. ^ a b Abt, Helmut A.; Morrell, Nidia I. (July 1995). "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars". The Astrophysical Journal Supplement Series. 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182. ISSN 0067-0049.
  6. ^ a b Feinstein, A. (April 1967). "Multicolor UBVRI observations of metallic-line stars". Publications of the Astronomical Society of the Pacific. 79: 184. Bibcode:1967PASP...79..184F. doi:10.1086/128464. eISSN 1538-3873. ISSN 0004-6280.
  7. ^ a b c d e Corbally, C. J. (August 1984). "Close visual binaries. I - MK classifications". The Astrophysical Journal Supplement Series. 55: 657. Bibcode:1984ApJS...55..657C. doi:10.1086/190973. eISSN 1538-4365. ISSN 0067-0049.
  8. ^ a b Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
  9. ^ Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
  10. ^ a b Allende Prieto, C.; Lambert, D. L. (December 1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. ISSN 0004-6361.
  11. ^ a b Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (October 2004). "The angular sizes of dwarf stars and subgiants". Astronomy & Astrophysics. 426 (1): 297–307. arXiv:astro-ph/0404180. Bibcode:2004A&A...426..297K. doi:10.1051/0004-6361:20035930. eISSN 1432-0746. ISSN 0004-6361.
  12. ^ a b Chandler, Colin Orion; McDonald, Iain; Kane, Stephen R. (17 February 2016). "The Catalog of Earth-Like Exoplanet Survey Targets (CELESTA): A Database of Habitable Zones Around Nearby Stars". The Astronomical Journal. 151 (3): 59. arXiv:1510.05666. Bibcode:2016AJ....151...59C. doi:10.3847/0004-6256/151/3/59. eISSN 1538-3881.
  13. ^ Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. eISSN 1538-3881. hdl:1721.1/124721. S2CID 166227927.
  14. ^ a b Schofield, Mathew; et al. (14 March 2019). "The Asteroseismic Target List for Solar-like Oscillators Observed in 2 minute Cadence with the Transiting Exoplanet Survey Satellite". The Astrophysical Journal Supplement Series. 241 (1): 12. arXiv:1901.10148. Bibcode:2019ApJS..241...12S. doi:10.3847/1538-4365/ab04f5. eISSN 1538-4365.
  15. ^ a b Huang, Su-Shu (September 1953). "A Statistical Study of the Rotation of the Stars". The Astrophysical Journal. 118: 285. Bibcode:1953ApJ...118..285H. doi:10.1086/145751. eISSN 1538-4357. ISSN 0004-637X.
  16. ^ a b c Anders, F.; et al. (February 2022). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia EDR3 stars brighter than G = 18.5". Astronomy & Astrophysics. 658: A91. arXiv:2111.01860. Bibcode:2022A&A...658A..91A. doi:10.1051/0004-6361/202142369. eISSN 1432-0746. ISSN 0004-6361.
  17. ^ a b Lang, Kenneth R. (2006). Astrophysical formulae. Astronomy and astrophysics library. Vol. 1 (3 ed.). Birkhäuser. ISBN 3-540-29692-1.. The radius (R*) is given by:
  18. ^ a b c Stevens, Daniel J.; Stassun, Keivan G.; Gaudi, B. Scott (29 November 2017). "Empirical Bolometric Fluxes and Angular Diameters of 1.6 Million Tycho-2 Stars and Radii of 350,000 Stars with Gaia DR1 Parallaxes". The Astronomical Journal. 154 (6): 259. arXiv:1708.05025. Bibcode:2017AJ....154..259S. doi:10.3847/1538-3881/aa957b. eISSN 1538-3881. S2CID 119191064.
  19. ^ a b c Gontcharov, G. A. (December 2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. eISSN 1562-6873. ISSN 1063-7737.
  20. ^ Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
  21. ^ "HR 8202". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 21 December 2022.
  22. ^ Gontcharov, George A.; Mosenkov, Aleksandr V. (28 September 2017). "Verifying reddening and extinction for Gaia DR1 TGAS main sequence stars". Monthly Notices of the Royal Astronomical Society. 472 (4): 3805–3820. arXiv:1709.01160. Bibcode:2017MNRAS.472.3805G. doi:10.1093/mnras/stx2219. eISSN 1365-2966. ISSN 0035-8711.
  23. ^ a b Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.
  24. ^ Tokovinin, Andrei (23 February 2018). "The Updated Multiple Star Catalog". The Astrophysical Journal Supplement Series. 235 (1): 6. arXiv:1712.04750. Bibcode:2018ApJS..235....6T. doi:10.3847/1538-4365/aaa1a5. eISSN 1538-4365.
This page was last edited on 28 February 2024, at 23:25
Basis of this page is in Wikipedia. Text is available under the CC BY-SA 3.0 Unported License. Non-text media are available under their specified licenses. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc. WIKI 2 is an independent company and has no affiliation with Wikimedia Foundation.
Contact WIKI 2
Introduction
Terms of Service
Privacy Policy