Főoldal     To Survive in the Universe    
Services
    Why to Inhabit     Top Contributors     Asztrofotók     Kollekció     Fórum     Blog New!     GYIK     Bejelentkezés  
→ Adopt this star  

HD 4108


Tartalom

Képek

Kép feltöltése

DSS Images   Other Images


Kapcsolódó cikkek

RE 0044+09: A new K dwarf rapid rotator with a white dwarf companion
We report the discovery of a new K dwarf rapid rotator with a potentialwhite dwarf companion. The white dwarf accounts for over 90% of theobserved extreme ultraviolet flux detected from this system. Analysis ofROSAT Wide Field Camera (WFC) and IUE data both suggest a white dwarftemperature of approximately 28,700 K. Optical photometry and the IUElong wavelength prime (LWP) spectrum (with the white dwarf contributionremoved) imply that the late-type star has a spectral type of K1-3 V,and a distance of 55 +/- 5 pc. Using this distance, the observed IUE SWPflux, and the best-fit temperature results in a white dwarf radius of0.0088 solar radius. The estimated white dwarf mass is thenapproximately 0.91 solar mass; somewhat over-massive compared to fieldwhite dwarfs. Optical photometry of the K star reveals a 'spot'modulation period of approximately 10 hr (now observed over 3 yr).However, radial velocity observations have revealed no significantvariations. Spectroscopic observations place a low limit on the lithiumabundance, but do show rapid rotation with a v sin i of 90 +/- 10 km/s.The K star was detected as a radio source at 3.6 cm (on two occasions)and 6 cm by the Very Large Array (VLA). The most likely evolutionaryscenario is that the K star and hot white dwarf from either a widebinary or common proper motion pair with an age of 0.1-0.1Gyr-consistent with the evolutionary timescale of the white dwarf andthe rapid rotation of the K star. However, from the proper motion of theK star, this system does not seem to be associated with any of the knownyoung stellar groups.

Photoelectric measurements of lunar occultation. VI. Further observational results.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973AJ.....78..482D&db_key=AST

Új cikk hozzáadása


Kapcsolódó hivatkozások

  • - (nincs kapcsolódó hivatkozás) -
Új link hozzáadása


Besorolás csoportokba:


Pozíciós és asztrometriai adatok

Csillagkép:Halak
Rektaszcenzió:00h43m37.07s
Deklináció:+10°04'43.9"
Vizuális fényesség:9.094
RA sajátmozgás:-38.4
Dec sajátmozgás:-55.1
B-T magnitude:9.702
V-T magnitude:9.145

Katalógusok és elnevezések:
Megfelelő nevek
HD 1989HD 4108
TYCHO-2 2000TYC 607-470-1
USNO-A2.0USNO-A2 0975-00153146
HIPHIP 3424

→ További katalógusok és elnevezések lekérése VizieR-ből