fbpx
Wikipedia

F-type main-sequence star

January 10, 2023

An F-type main-sequence star (F V) is a main-sequence, hydrogen-fusing star of spectral type F and luminosity class V. These stars have from 1.0 to 1.4 times the mass of the Sun and surface temperatures between 6,000 and 7,600 K.[2]Tables VII and VIII. This temperature range gives the F-type stars a whitish hue when observed by the atmosphere. Because a main-sequence star is referred to as a dwarf star, this class of star may also be termed a yellow-white dwarf (not to be confused with white dwarfs, remnant stars that are a possible final stage of stellar evolution). Notable examples include Procyon A, Gamma Virginis A and B,[3] and KIC 8462852.[4]

Disc of debris around an F-type star[1]

Spectral standard stars

Properties of typical F-type main-sequence stars[5][6]
Spectral
type 		Mass (M☉) Radius (R☉) Luminosity (L☉) Effective
temperature
(K) 		Color
index
(B − V)
F0V 1.61 1.728 7.24 7,220 0.30
F1V 1.50 1.679 6.17 7,020 0.33
F2V 1.46 1.622 5.13 6,820 0.37
F3V 1.44 1.578 4.68 6,750 0.39
F4V 1.38 1.533 4.17 6,670 0.41
F5V 1.33 1.473 3.63 6,550 0.44
F6V 1.25 1.359 2.69 6,350 0.49
F7V 1.21 1.324 2.45 6,280 0.50
F8V 1.18 1.221 1.95 6,180 0.53
F9V 1.13 1.167 1.66 6,050 0.56

The revised Yerkes Atlas system (Johnson & Morgan 1953)[7] listed a dense grid of F-type dwarf spectral standard stars; however, not all of these have survived to this day as stable standards. The anchor points of the MK spectral classification system among the F-type main-sequence dwarf stars, i.e. those standard stars that have remained unchanged over years and can be used to define the system, are considered to be 78 Ursae Majoris (F2 V) and pi3 Orionis (F6 V).[8] In addition to those two standards, Morgan & Keenan (1973)[9] considered the following stars to be dagger standards: HR 1279 (F3 V), HD 27524 (F5 V), HD 27808 (F8 V), HD 27383 (F9 V), and Beta Virginis (F9 V). Other primary MK standard stars include HD 23585 (F0 V), HD 26015 (F3 V), and HD 27534 (F5 V).[10] Note that two Hyades members with almost identical HD names (HD 27524 and HD 27534) are both considered strong F5 V standard stars, and indeed they share nearly identical colors and magnitudes. Gray & Garrison (1989)[11]</ref> provide a modern table of dwarf standards for the hotter F-type stars. F1 and F7 dwarf standards stars are rarely listed, but have changed slightly over the years among expert classifiers. Often-used standard stars in this class include 37 Ursae Majoris (F1 V) and Iota Piscium (F7 V). No F4 V standard stars currently have been officially published yet. Unfortunately F9 V defines the boundary between the hot stars classified by Morgan, and the cooler stars classified by Keenan a step lower, and there are discrepancies in the literature on which stars define the F/G dwarf boundary. Morgan & Keenan (1973)[9] listed Beta Virginis and HD 27383 as F9 V standards, but Keenan & McNeil (1989)[12] listed HD 10647 as their F9 V standard instead. Eta Cassiopeiae A should probably be avoided as a standard star, but maybe as a boundary star, because it was often considered F9 V in Keenan's publications,[12] but G0 V in Morgan's publications.[10]

Life cycle

F-type stars have a life-cycle similar to G-type stars. They are hydrogen-fusing and will eventually grow into a red giant that fuses helium instead of hydrogen once their supply of hydrogen is depleted. After the helium too runs out, they begin to fuse carbon. When that also runs out, they shed their outer layers, creating a planetary nebula, and leaving behind, at the center of the nebula, a hot white dwarf. These stars remain stable for ~2-4 billion years. In comparison, G-type stars, like the Sun, stay stable for ~10 billion years.[13]

Planets

Some of the nearest F-type stars known to support planets include Upsilon Andromedae, Tau Boötis, HD 10647, HD 33564, HD 142, HD 60532, and KOI-3010.

Habitability

Some studies show that there is a possibility that life could also develop on planets that orbit an F-type star.[14] It is estimated that the habitable zone of a relatively hot F0 star would extend from about 2.0 AU to 3.7 AU and between 1.1 and 2.2 AU for a relatively cool F8 star.[14] However, relative to a G-type star the main problems for a hypothetical lifeform in this particular scenario would be the more intense light and the shorter stellar lifespan of the home star.[14]

F-type stars are known to emit much higher energy forms of light, such as UV radiation, which in the long term can have a profoundly negative effect on DNA molecules.[14] Studies have shown that, for a hypothetical planet positioned at an equivalent habitable distance from an F-type star as the Earth is from the Sun (this is farther away from the F-type star, inside the habitable zone of a G2-type), and with a similar atmosphere, life on its surface would receive about 2.5 to 7.1 times more damage from UV light compared to that on Earth.[15] Thus, for its native lifeforms to survive, the hypothetical planet would need to have sufficient atmospheric shielding, such as a denser ozone layer in the upper atmosphere.[14] Without a robust ozone layer, life could theoretically develop on the planet's surface, but it would most likely be confined to underwater or underground regions or has somehow adapted external covering against (e.g. shells).[14][16]

References

  1. ^ "New Insights into Debris Discs". Retrieved 23 May 2016.
  2. ^ Habets, G. M. H. J.; Heintze, J. R. W. (November 1981). "Empirical bolometric corrections for the main-sequence". Astronomy and Astrophysics Supplement. 46: 193–237. Bibcode:1981A&AS...46..193H.
  3. ^ SIMBAD, entries on Gamma Virginis A, Gamma Virginis B, accessed June 19, 2007.
  4. ^ "The Curious Case of KIC 8462852". Sky & Telescope. 2015-10-21. Retrieved 2022-05-02.
  5. ^ Pecaut, Mark J.; Mamajek, Eric E. (1 September 2013). "Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-main-sequence Stars". The Astrophysical Journal Supplement Series. 208 (1): 9. arXiv:1307.2657. Bibcode:2013ApJS..208....9P. doi:10.1088/0067-0049/208/1/9. ISSN 0067-0049. S2CID 119308564.
  6. ^ Mamajek, Eric (2 March 2021). "A Modern Mean Dwarf Stellar Color and Effective Temperature Sequence". University of Rochester, Department of Physics and Astronomy. Retrieved 5 July 2021.
  7. ^ Johnson, H. L.; Morgan, W. W. (1953). "Fundamental stellar photometry for standards of spectral type on the revised system of the Yerkes spectral atlas". The Astrophysical Journal. 117 (3): 313–352. Bibcode:1953ApJ...117..313J. doi:10.1086/145697.
  8. ^ Robert F. Garrison. "MK Anchor Points". Retrieved 2022-10-30.
  9. ^ a b Morgan, W. W.; Keenan, P. C. (1973). "Spectral Classification". Annual Review of Astronomy and Astrophysics. 11: 29. Bibcode:1973ARA&A..11...29M. doi:10.1146/annurev.aa.11.090173.000333.
  10. ^ a b Morgan, W. W.; Abt, Helmut A.; Tapscott, J. W. (1978). Revised MK Spectral Atlas for stars earlier than the sun. Yerkes Observatory, University of Chicago. Bibcode:1978rmsa.book.....M.
  11. ^ Gray, R. O; Garrison, R. F (1989). "The early F-type stars - Refined classification, confrontation with Stromgren photometry, and the effects of rotation". Astrophysical Journal Supplement Series. 69: 301. Bibcode:1989ApJS...69..301G. doi:10.1086/191315.
  12. ^ a b Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373.
  13. ^ Guide, Universe (2019-04-07). "F Type Star (Yellow/White)". Universe Guide. Retrieved 2022-05-03.
  14. ^ a b c d e f Hadhazy, Adam (1 May 2014). "Could Alien Life Cope with a Hotter, Brighter Star?". space.com. Space.com. Retrieved 31 March 2018.
  15. ^ Cuntz, M.; Wang, Zh; Sato, S. (9 March 2015). "Climatological and UV-based Habitability of Possible Exomoons in F-star Systems". Astronomische Nachrichten. arXiv:1503.02560. doi:10.1002/asna.201613279. S2CID 118668172.
  16. ^ Sato, S.; Cuntz, M.; Olvera, C. M. Guerra; Jack, D.; Schröder, K.-P. (July 2014). "Habitability around F-type stars". International Journal of Astrobiology. 13 (3): 244–258. arXiv:1312.7431. Bibcode:2014IJAsB..13..244S. doi:10.1017/S1473550414000020. ISSN 1473-5504. S2CID 119101988.

January 10, 2023
type, main, sequence, star, main, sequence, hydrogen, fusing, star, spectral, type, luminosity, class, these, stars, have, from, times, mass, surface, temperatures, between, tables, viii, this, temperature, range, gives, type, stars, whitish, when, observed, a. An F type main sequence star F V is a main sequence hydrogen fusing star of spectral type F and luminosity class V These stars have from 1 0 to 1 4 times the mass of the Sun and surface temperatures between 6 000 and 7 600 K 2 Tables VII and VIII This temperature range gives the F type stars a whitish hue when observed by the atmosphere Because a main sequence star is referred to as a dwarf star this class of star may also be termed a yellow white dwarf not to be confused with white dwarfs remnant stars that are a possible final stage of stellar evolution Notable examples include Procyon A Gamma Virginis A and B 3 and KIC 8462852 4 Disc of debris around an F type star 1 Contents 1 Spectral standard stars 2 Life cycle 3 Planets 4 Habitability 5 ReferencesSpectral standard stars EditProperties of typical F type main sequence stars 5 6 Spectraltype Mass M Radius R Luminosity L Effectivetemperature K Colorindex B V F0V 1 61 1 728 7 24 7 220 0 30F1V 1 50 1 679 6 17 7 020 0 33F2V 1 46 1 622 5 13 6 820 0 37F3V 1 44 1 578 4 68 6 750 0 39F4V 1 38 1 533 4 17 6 670 0 41F5V 1 33 1 473 3 63 6 550 0 44F6V 1 25 1 359 2 69 6 350 0 49F7V 1 21 1 324 2 45 6 280 0 50F8V 1 18 1 221 1 95 6 180 0 53F9V 1 13 1 167 1 66 6 050 0 56The revised Yerkes Atlas system Johnson amp Morgan 1953 7 listed a dense grid of F type dwarf spectral standard stars however not all of these have survived to this day as stable standards The anchor points of the MK spectral classification system among the F type main sequence dwarf stars i e those standard stars that have remained unchanged over years and can be used to define the system are considered to be 78 Ursae Majoris F2 V and pi3 Orionis F6 V 8 In addition to those two standards Morgan amp Keenan 1973 9 considered the following stars to be dagger standards HR 1279 F3 V HD 27524 F5 V HD 27808 F8 V HD 27383 F9 V and Beta Virginis F9 V Other primary MK standard stars include HD 23585 F0 V HD 26015 F3 V and HD 27534 F5 V 10 Note that two Hyades members with almost identical HD names HD 27524 and HD 27534 are both considered strong F5 V standard stars and indeed they share nearly identical colors and magnitudes Gray amp Garrison 1989 11 lt ref gt provide a modern table of dwarf standards for the hotter F type stars F1 and F7 dwarf standards stars are rarely listed but have changed slightly over the years among expert classifiers Often used standard stars in this class include 37 Ursae Majoris F1 V and Iota Piscium F7 V No F4 V standard stars currently have been officially published yet Unfortunately F9 V defines the boundary between the hot stars classified by Morgan and the cooler stars classified by Keenan a step lower and there are discrepancies in the literature on which stars define the F G dwarf boundary Morgan amp Keenan 1973 9 listed Beta Virginis and HD 27383 as F9 V standards but Keenan amp McNeil 1989 12 listed HD 10647 as their F9 V standard instead Eta Cassiopeiae A should probably be avoided as a standard star but maybe as a boundary star because it was often considered F9 V in Keenan s publications 12 but G0 V in Morgan s publications 10 Life cycle EditF type stars have a life cycle similar to G type stars They are hydrogen fusing and will eventually grow into a red giant that fuses helium instead of hydrogen once their supply of hydrogen is depleted After the helium too runs out they begin to fuse carbon When that also runs out they shed their outer layers creating a planetary nebula and leaving behind at the center of the nebula a hot white dwarf These stars remain stable for 2 4 billion years In comparison G type stars like the Sun stay stable for 10 billion years 13 Planets EditSome of the nearest F type stars known to support planets include Upsilon Andromedae Tau Bootis HD 10647 HD 33564 HD 142 HD 60532 and KOI 3010 Habitability EditSome studies show that there is a possibility that life could also develop on planets that orbit an F type star 14 It is estimated that the habitable zone of a relatively hot F0 star would extend from about 2 0 AU to 3 7 AU and between 1 1 and 2 2 AU for a relatively cool F8 star 14 However relative to a G type star the main problems for a hypothetical lifeform in this particular scenario would be the more intense light and the shorter stellar lifespan of the home star 14 F type stars are known to emit much higher energy forms of light such as UV radiation which in the long term can have a profoundly negative effect on DNA molecules 14 Studies have shown that for a hypothetical planet positioned at an equivalent habitable distance from an F type star as the Earth is from the Sun this is farther away from the F type star inside the habitable zone of a G2 type and with a similar atmosphere life on its surface would receive about 2 5 to 7 1 times more damage from UV light compared to that on Earth 15 Thus for its native lifeforms to survive the hypothetical planet would need to have sufficient atmospheric shielding such as a denser ozone layer in the upper atmosphere 14 Without a robust ozone layer life could theoretically develop on the planet s surface but it would most likely be confined to underwater or underground regions or has somehow adapted external covering against e g shells 14 16 References Edit New Insights into Debris Discs Retrieved 23 May 2016 Habets G M H J Heintze J R W November 1981 Empirical bolometric corrections for the main sequence Astronomy and Astrophysics Supplement 46 193 237 Bibcode 1981A amp AS 46 193H SIMBAD entries on Gamma Virginis A Gamma Virginis B accessed June 19 2007 The Curious Case of KIC 8462852 Sky amp Telescope 2015 10 21 Retrieved 2022 05 02 Pecaut Mark J Mamajek Eric E 1 September 2013 Intrinsic Colors Temperatures and Bolometric Corrections of Pre main sequence Stars The Astrophysical Journal Supplement Series 208 1 9 arXiv 1307 2657 Bibcode 2013ApJS 208 9P doi 10 1088 0067 0049 208 1 9 ISSN 0067 0049 S2CID 119308564 Mamajek Eric 2 March 2021 A Modern Mean Dwarf Stellar Color and Effective Temperature Sequence University of Rochester Department of Physics and Astronomy Retrieved 5 July 2021 Johnson H L Morgan W W 1953 Fundamental stellar photometry for standards of spectral type on the revised system of the Yerkes spectral atlas The Astrophysical Journal 117 3 313 352 Bibcode 1953ApJ 117 313J doi 10 1086 145697 Robert F Garrison MK Anchor Points Retrieved 2022 10 30 a b Morgan W W Keenan P C 1973 Spectral Classification Annual Review of Astronomy and Astrophysics 11 29 Bibcode 1973ARA amp A 11 29M doi 10 1146 annurev aa 11 090173 000333 a b Morgan W W Abt Helmut A Tapscott J W 1978 Revised MK Spectral Atlas for stars earlier than the sun Yerkes Observatory University of Chicago Bibcode 1978rmsa book M Gray R O Garrison R F 1989 The early F type stars Refined classification confrontation with Stromgren photometry and the effects of rotation Astrophysical Journal Supplement Series 69 301 Bibcode 1989ApJS 69 301G doi 10 1086 191315 a b Keenan Philip C McNeil Raymond C 1989 The Perkins catalog of revised MK types for the cooler stars Astrophysical Journal Supplement Series 71 245 Bibcode 1989ApJS 71 245K doi 10 1086 191373 Guide Universe 2019 04 07 F Type Star Yellow White Universe Guide Retrieved 2022 05 03 a b c d e f Hadhazy Adam 1 May 2014 Could Alien Life Cope with a Hotter Brighter Star space com Space com Retrieved 31 March 2018 Cuntz M Wang Zh Sato S 9 March 2015 Climatological and UV based Habitability of Possible Exomoons in F star Systems Astronomische Nachrichten arXiv 1503 02560 doi 10 1002 asna 201613279 S2CID 118668172 Sato S Cuntz M Olvera C M Guerra Jack D Schroder K P July 2014 Habitability around F type stars International Journal of Astrobiology 13 3 244 258 arXiv 1312 7431 Bibcode 2014IJAsB 13 244S doi 10 1017 S1473550414000020 ISSN 1473 5504 S2CID 119101988 Retrieved from https en wikipedia org w index php title F type main sequence star amp oldid 1119072340, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.