KY Cygni

From testwiki
Jump to navigation Jump to search

Template:Short description Template:Starbox begin Template:Starbox image Template:Starbox observe Template:Starbox character Template:Starbox astrometry Template:Starbox detail Template:Starbox catalog Template:Starbox reference Template:Starbox end

KY Cygni is a variable red supergiant of spectral class M3Ia located in the constellation Cygnus. It is approximately 4,700 light-years away.

Observations

KY Cyg lies near the bright open cluster NGC 6913, but is not thought to be a member. The location is close to the bright star γ Cygni.[1] It was identified as a variable star in 1930,[2] and later named as KY Cygni.[3] The spectrum was given the MK classification of M3 Ia, with only minor adjustments since.[4]

KY Cygni is heavily reddened due to interstellar extinction, losing an estimated 7.75 magnitudes at visual wavelengths. It would be a naked eye star if no light was lost.[5]

Properties

Size comparison of Betelgeuse, Mu Cephei, KY Cygni, and V354 Cephei, according to estimates derived in 2005[5]

KY Cygni is classified as a luminous red supergiant with a strong stellar wind. It is losing mass at around Template:Val and has been described as a cool hypergiant.[6][7]

Its properties are uncertain, but the temperature is around 3,500 K. A model fit based on K-band infrared brightness gives a luminosity of Template:Solar luminosity, corresponding to a radius of Template:Solar radius. Another model based on visual brightness gives an unexpectedly large luminosity of Template:Solar luminosity, with the difference due mainly to the assumptions about the level of extinction. The radius corresponding to the higher luminosity would be Template:Solar radius. These parameters are larger and more luminous than expected for any red supergiant, making them doubtful.[5] More recently, integration of the spectral energy distributions across a full range of wavelengths from U band to the 60 micron microwave flux gives an even lower luminosity of Template:Solar luminosity,[6] and a 2020 paper published a luminosity of Template:Solar luminosity, which give a smaller radius of Template:Solar radius calculator using an effective temperature of 3,535Template:NbspK.[8]

A visual band light curve for KY Cygni, plotted from data published by Kochanek et al. (2017)[9]

KY Cygni is a variable star with a large amplitude but no clear periodicity. At times, it varies rapidly, at others it is fairly constant for long periods.[1] The photographic magnitude range is given as 13.5 - 15.5,[10] while a visual range is 10.60 - 11.74.[11]

Template:Clear left

See also

Notes

Template:Notelist

References

Template:Reflist

Template:Stars of Cygnus

  1. ↑ 1.0 1.1 Template:Cite journal
  2. ↑ Template:Cite journal
  3. ↑ Template:Cite journal
  4. ↑ Template:Cite journal
  5. ↑ 5.0 5.1 5.2 Cite error: Invalid <ref> tag; no text was provided for refs named levesque
  6. ↑ 6.0 6.1 Cite error: Invalid <ref> tag; no text was provided for refs named mauron
  7. ↑ Template:Cite journal
  8. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named Comeron
  9. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named Kochanek
  10. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named gcvs1
  11. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named alfonso-garzon
Retrieved from "https://en.wiki.beta.math.wmflabs.org/w/index.php?title=KY_Cygni&oldid=14541"