Astronomy:Iota Cancri

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Short description: Double star in the constellation Cancer
ι Cancri
Cancer constellation map.svg
Red circle.svg
Location of ι Cancri (circled)
Observation data
{{#ifeq:J2000.0|J2000.0 (ICRS)|Epoch J2000.0      Equinox J2000.0 (ICRS)| [[History:Epoch|Epoch J2000.0]]      [[Astronomy:Equinox (celestial coordinates)|Equinox J2000.0}}
Constellation Cancer
ι Cnc A
Right ascension  08h 46m 41.81988s[1]
Declination +28° 45′ 35.6190″[1]
Apparent magnitude (V) 4.02[2]
ι Cnc B
Right ascension  08h 46m 39.98118s[1]
Declination +28° 45′ 54.1932″[1]
Apparent magnitude (V) 6.57[3]
Characteristics
Spectral type G8IIIa Ba0.2[4] + A2V[5]
Astrometry
ι Cnc A
Radial velocity (Rv)15.74 ± 0.13[6] km/s
Proper motion (μ) RA: -21.58 ± 0.75[1] mas/yr
Dec.: -45.69 ± 0.56[1] mas/yr
Parallax (π)9.85 ± 0.61[1] mas
Distance330 ± 20 ly
(102 ± 6 pc)
Absolute magnitude (MV)−0.79[7]
ι Cnc B
Radial velocity (Rv)25.00 ± 1.5[8] km/s
Proper motion (μ) RA: -22.74 ± 3.45[1] mas/yr
Dec.: -46.36 ± 2.56[1] mas/yr
Parallax (π)11.69 ± 2.75[1] mas
Distanceapprox. 280 ly
(approx. 90 pc)
Details
ι Cnc A
Mass3.43[9] M
Radius21[6] R
Luminosity204[6] L
Surface gravity (log g)2.5[6] cgs
Temperature4,954[7] K
Metallicity [Fe/H]−0.14[6] dex
Rotational velocity (v sin i)170[10] km/s
ι Cnc B
Luminosity14.39[11] L
Temperature8,786[11] K
Age263[9] Myr
Other designations
48 Cancri
Iota Cancri A: HR 3475, HD 74739, BD+29°1824, HIP 43103, SAO 80416
Iota Cancri B: HR 3474, HD 74738, BD+29°1823, HIP 43100, SAO 80415
Database references
SIMBADdata
ι Cancri A and B (Jeffrey Fisher)

Iota Cancri (ι Cnc, ι Cancri) is a double star in the constellation Cancer approximately 300 light years from Earth.

The two stars of ι Cancri are separated by 30 arcseconds, changing only slowly. Although no orbit has been derived, the two stars show a large common proper motion and are assumed to be gravitationally related.[12]

The brighter star, ι Cancri A, is a yellow G-type giant with an apparent magnitude of +4.02. It is a mild barium star, thought to be formed by mass transfer of enriched material from an asymptotic giant branch star onto a less evolved companion. No such donor has been detected in the ι Cancri system, but it is assumed that there is an unseen white dwarf.[13]

The fainter of the two stars, ι Cancri B, is a white A-type main sequence dwarf with an apparent magnitude of +6.57. It is a shell star, surrounded by material expelled by its rapid rotation.[14]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode2007A&A...474..653V. 
  2. Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode1986EgUBV........0M. 
  3. Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues 2237. Bibcode2002yCat.2237....0D. 
  4. Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series 71: 245. doi:10.1086/191373. Bibcode1989ApJS...71..245K. 
  5. Grenier, S.; Baylac, M.-O.; Rolland, L.; Burnage, R.; Arenou, F.; Briot, D.; Delmas, F.; Duflot, M. et al. (1999). "Radial velocities. Measurements of 2800 B2-F5 stars for HIPPARCOS". Astronomy and Astrophysics Supplement 137 (3): 451. doi:10.1051/aas:1999489. Bibcode1999A&AS..137..451G. https://hal.archives-ouvertes.fr/hal-02053966/file/Grenier%20et%20al.%20-%201999%20-%20Radial%20velocities.%20Measurements%20of%202800%20B2-F5%20star.pdf. 
  6. 6.0 6.1 6.2 6.3 6.4 Massarotti, Alessandro; Latham, David W.; Stefanik, Robert P.; Fogel, Jeffrey (2008). "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity". The Astronomical Journal 135 (1): 209–231. doi:10.1088/0004-6256/135/1/209. Bibcode2008AJ....135..209M. 
  7. 7.0 7.1 Kovtyukh, V. V.; Chekhonadskikh, F. A.; Luck, R. E.; Soubiran, C.; Yasinskaya, M. P.; Belik, S. I. (2010). "Accurate luminosities for F-G supergiants from FeII/FeI line depth ratios". Monthly Notices of the Royal Astronomical Society 408 (3): 1568. doi:10.1111/j.1365-2966.2010.17217.x. Bibcode2010MNRAS.408.1568K. 
  8. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode2006AstL...32..759G. 
  9. 9.0 9.1 Takeda, Yoichi; Sato, Bun'ei; Murata, Daisuke (2008). "Stellar Parameters and Elemental Abundances of Late-G Giants". Publications of the Astronomical Society of Japan 60 (4): 781. doi:10.1093/pasj/60.4.781. Bibcode2008PASJ...60..781T. 
  10. Royer, F.; Grenier, S.; Baylac, M.-O.; Gómez, A. E.; Zorec, J. (2002). "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i". Astronomy and Astrophysics 393 (3): 897–912. doi:10.1051/0004-6361:20020943. Bibcode2002A&A...393..897R. 
  11. 11.0 11.1 McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (2012). "Fundamental parameters and infrared excesses of Hipparcos stars". Monthly Notices of the Royal Astronomical Society 427 (1): 343–357. doi:10.1111/j.1365-2966.2012.21873.x. Bibcode2012MNRAS.427..343M. 
  12. Eggen, Olin J. (1994). "Photometry of F-K type bright giants and supergiants. 3: The luminosity, reddening, and heavy element abundance of GK stars". The Astronomical Journal 107: 2184. doi:10.1086/117030. Bibcode1994AJ....107.2184E. 
  13. Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society 389 (2): 869. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode2008MNRAS.389..869E. 
  14. Hauck, B.; Jaschek, C. (2000). "A-shell stars in the Geneva system". Astronomy and Astrophysics 354: 157. Bibcode2000A&A...354..157H.