An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 3 Search : metal-poor
carbon-enhanced metal-poor star (CEMP)
  ستاره‌ی ِ کم‌فلز ِ کربون بلندیده   
setâre-ye kamfelez-e karbon bolandidé

Fr.: étoile pauvre en métaux enrichie en carbon   

A star that presents very low → iron  → abundances [Fe/H] < -4 but an → anomalous richness in carbon. CEMP stars have been defined as a subset of → metal-poor stars that exhibit elevated [C/Fe] ≥ +1.0. It has been recognized that ~15-20% of stars with [Fe/H] < -2.0 are carbon enhanced. This fraction rises to 30% for [Fe/H] < -3.0, to 40% for [Fe/H] < -3.5, and ~75% for [Fe/H] < -4.0. This increasing trend of CEMP-star frequency with declining [Fe/H] is confirmed by the observation of many thousands of CEMP stars (Daniela Carollo + ApJ 2014, 788, 180). See also → extremely metal-poor star (EMPS)

carbon; → enhance; → metal; → metal; → poor; → star.

extremely metal-poor star (EMPS)
  ستاره‌ی ِ اُستومانه کم‌فلز   
stâre-ye ostomâné kamfelez

Fr.: étoile extrêmement faible en métaux   

A star with an iron abundance [Fe/H] < -3 found in a → galactic halo. These stars, whose → metallicity is typically less than one thousandth of the solar value, are believed to have formed shortly after the → Big Bang, 13.7 billion years ago. The number of such stars depends on the primordial → initial mass function. If the IMF were steep, there could, in principle, be a lot of EMPSs formed at high → redshifts. Thus many of them could have ended up in the halos of galaxies. See also → Population III star.

extreme; → metal; → poor; → star.

metal-poor galaxy
  کهکشان ِ کم‌فلز   
kahkešân-e kamfelez

Fr.: galaxie pauvre en métaux   

Same as → metal-deficient galaxy.

metal; → poor; → galaxy.