HD 40307

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Template:Short description

HD 40307
File:Location of HD 40307.png
Location of HD 40307 in the night sky. The star is marked within the red diamond below the word "Pictor".
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Pictor
Right ascension Template:RA[1]
Declination Template:DEC[1]
Apparent magnitude (V) 7.17[2]
Characteristics
Spectral type K2.5V[2]
B−V Template:Engvar 0.93[2]
Astrometry
Radial velocity (Rv)Script error: No such module "val".[1] km/s
Proper motion (μ) RA: Script error: No such module "val". mas/yr[1]
Dec.: Script error: No such module "val". mas/yr[1]
Parallax (π)77.3261±0.0170 mas[1]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)Script error: No such module "val".[3]
Details
Mass0.75Script error: No such module "Su".[4] Template:Solar mass
Radius0.716 ± 0.010[5] Template:Solar radius
Luminosity (bolometric)0.23[6] Template:Solar luminosity
Luminosity (visual, LV)0.20[note 1] Template:Solar luminosity
Surface gravity (log g)4.47 ± 0.16[6] cgs
Temperature4977 ± 59[6] K
Metallicity [Fe/H]−0.31 ± 0.03[6] dex
RotationScript error: No such module "val".[7]
Rotational velocity (v sin i)3[4] km/s
Age1.2 (≥ 0.2)[4] Gyr
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
CD−60 1303, CPD−60 508, GC 7474, GJ 2046, HIP 27887, PPM 355061, SAO 249388, 2MASS J05540421-6001245.[2]
Database references
SIMBADdata
Exoplanet Archivedata
ARICNSdata

Script error: No such module "Check for unknown parameters".

HD 40307 is an orange (K-type) main-sequence star located approximately 42 light-years away in the constellation of Pictor (the Easel), taking its primary name from its Henry Draper Catalogue designation. It is calculated to be slightly less massive than the Sun. The star has six known planets, three discovered in 2008[2][8] and three more in 2012. One of them, HD 40307 g, is a potential super-Earth in the habitable zone, with an orbital period of about 200 days. This object might be capable of supporting liquid water on its surface, although much more information must be acquired before its habitability can be assessed.[9][10][11][12]

No stellar companions to HD 40307 were detected as of 2018.[13]

History and nomenclature

HD 40307 was observed during or before 1900 as part of the Cape Photographic Durchmusterung.[14] The designation HD 40307 is from the Henry Draper Catalogue, which is based on spectral classifications made between 1911 and 1915 by Annie Jump Cannon and her co-workers, and was published between 1918 and 1924.[15][16]

Characteristics

As a K-type star, HD 40307 emits orange-tinted light.[2] It has only about three-quarters of the Sun's radius and mass.[4] Its temperature is measured at slightly under Script error: No such module "val"..

The astronomers who discovered the planets orbiting HD 40307 suggested that the metallicities of stars determine whether or not the planetary bodies that orbit them will be terrestrial, like Earth, or gaseous, like Jupiter and Saturn.[6]

Distance and visibility

Despite its relative proximity to the Sun at 42 light-years, HD 40307 is not visible to the naked eye, given its apparent magnitude of 7.17.[17] It came within 6.4 light-years of the Sun about 413,000 years ago.[18]

Planetary system

A planetary system around HD 40307 contains four confirmed planets and two other possible planets, all within Script error: No such module "val". of the star. Template:OrbitboxPlanet begin Template:OrbitboxPlanet Template:OrbitboxPlanet Template:OrbitboxPlanet Template:OrbitboxPlanet hypothetical Template:OrbitboxPlanet Template:OrbitboxPlanet hypothetical

|}Script error: No such module "Check for unknown parameters".

File:HD40307.svg
The orbits of the inner three planets of HD 40307.

After spending five years observing the star,[19] the European Organisation for Astronomical Research in the Southern Hemisphere (ESO) announced that they had discovered three super-Earths in orbit around HD 40307 in June 2008. All three planets were detected by the radial velocity method, using the HARPS spectrograph system.[20]

In 2012, an independent analysis carried out by a team of astronomers led by Mikko Tuomi of the University of Hertfordshire confirmed the existence of these planets and found an additional three planets in the systems.[9][10] The planet HD 40307 f on 51.6-day orbit was confirmed in 2015, with inconclusive evidence for the planets HD 40307 e and HD 40307 g.[21]

Five of the planets orbit very close to the star,[10] with the farthest of them located twice as close to HD 40307 than is the planet Mercury is to the Sun.[22][note 2] The outermost planet orbits at a distance similar to the distance of Venus to the Sun and is situated well in the system's liquid water habitable zone.[10]

The minimum masses of the planets in the system ranges from three to ten times the mass of the Earth, placing them somewhere between Earth and gas giants like Uranus and Neptune.[10] Dynamical analysis of the innermost planets suggests that planet b is unstable at its age unless it is an ice giant, having migrated from further away. That implies similar for the other planets, even further out.[23] The most recent discovery also indicates via dynamical analysis that the true planetary masses can not be much higher than their minimum masses.[10]

See also

Notes

  1. ↑ Using the absolute visual magnitude of HD 40307 MV∗=6.57 and the absolute visual magnitude of the Sun MV⊙=4.83, the visual luminosity can be calculated by LV∗LV⊙=100.4(MV⊙−MV∗)
  2. ↑ Mercury orbits at approx. 0.39 AU

References

<templatestyles src="Reflist/styles.css" />

  1. ↑ a b c d e Template:Cite Gaia DR3
  2. ↑ a b c d e f HD 40307, entry, SIMBAD. Accessed online June 18, 2008.
  3. ↑ Script error: No such module "Citation/CS1".VizieR
  4. ↑ a b c d HD 40307, database entry, Geneva-Copenhagen Survey of Solar neighbourhood, J. Holmberg et al., 2007, CDS database V/117A, accessed November 19, 2008; described in The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ~14 000 F and G dwarfs, B. Nordström, M. Mayor, J. Andersen, J. Holmberg, F. Pont, B. R. Jørgensen, E. H. Olsen, S. Udry, and N. Mowlavi, Astronomy and Astrophysics 418 (May 2004), pp. 989–1019, Bibcode:2004A&A...418..989NScript error: No such module "check bibcode"., Script error: No such module "CS1 identifiers"..
  5. ↑ HD 40307, entry, CDS database J/A+A/450/735; described in Effective temperature scale and bolometric corrections from 2MASS photometry, E. Masana, C. Jordi, and I. Ribas, Astronomy and Astrophysics 450, #2 (May 2006), pp. 735–746. Bibcode:2006A&A...450..735MScript error: No such module "check bibcode".. Script error: No such module "CS1 identifiers"..
  6. ↑ a b c d e Script error: No such module "Citation/CS1".
  7. ↑ Script error: No such module "Citation/CS1".
  8. ↑ Script error: No such module "citation/CS1".
  9. ↑ a b Script error: No such module "citation/CS1".
  10. ↑ a b c d e f Script error: No such module "Citation/CS1".
  11. ↑ Script error: No such module "citation/CS1".
  12. ↑ Script error: No such module "citation/CS1".
  13. ↑ Script error: No such module "Citation/CS1".
  14. ↑ CPD−60 508, database entry, Cape Photographic Durchmusterung (CPD), D. Gill and J. C. Kapetyn, 1895–1900, CDS ID I/108.
  15. ↑ pp. 214–215 in The Henry Draper Memorial, Annie J. Cannon, Journal of the Royal Astronomical Society of Canada 9, #5 (May–June 1915), pp. 203–215, Bibcode:1915JRASC...9..203CScript error: No such module "check bibcode"..
  16. ↑ The Henry Draper Catalogue, Annie J. Cannon and Edward C. Pickering, Annals of Harvard College Observatory;
    hours 0 to 3, 91 (1918), Bibcode:1918AnHar..91....1CScript error: No such module "check bibcode".;
    hours 4 to 6, 92 (1918), Bibcode:1918AnHar..92....1CScript error: No such module "check bibcode".;
    hours 7 to 8, 93 (1919), Bibcode:1919AnHar..93....1CScript error: No such module "check bibcode".;
    hours 9 to 11, 94 (1919), Bibcode:1919AnHar..94....1CScript error: No such module "check bibcode".;
    hours 12 to 14, 95 (1920), Bibcode:1920AnHar..95....1CScript error: No such module "check bibcode".;
    hours 15 to 16, 96 (1921), Bibcode:1921AnHar..96....1CScript error: No such module "check bibcode".;
    hours 17 to 18, 97 (1922), Bibcode:1922AnHar..97....1CScript error: No such module "check bibcode".;
    hours 19 to 20, 98 (1923), Bibcode:1923AnHar..98....1CScript error: No such module "check bibcode".;
    hours 21 to 23, 99 (1924), Bibcode:1924AnHar..99....1CScript error: No such module "check bibcode"..
  17. ↑ Script error: No such module "citation/CS1".
  18. ↑ Script error: No such module "Citation/CS1".
  19. ↑ Script error: No such module "citation/CS1".
  20. ↑ Script error: No such module "citation/CS1".
  21. ↑ Script error: No such module "Citation/CS1".
  22. ↑ Script error: No such module "citation/CS1".
  23. ↑ Script error: No such module "Citation/CS1".

Script error: No such module "Check for unknown parameters".

External links

Template:Sister project

Template:Sky Template:Good article

Template:HD 40307 Template:Stars of Pictor Template:2012 in space

Retrieved from "http://debianws.lexgopc.com/wiki143/index.php?title=HD_40307&oldid=6916941"