Carbon depletion in the envelopes of main sequence stars

Journal Article · Mon Jan 01 04:00:00 EST 1973 · Acta Astron., v. 23, no. 3, pp. 191-196

OSTI ID:4325330

Paczynski, B

It is shown that meridional (Eddington-Vogt) circulation in the envelopes of rotating main-sequence stars may bring up to the stellar surface nitrogen produced from carbon in the CNO bi-cycle. The required nuclear reactions take place outside the convective core, in a region where there is no mu gradient that could suppress the meridional circulation. Carbon depletion was calculated for the envelopes of model main-sequence stars in the mass range from 0.8 to 60.0 solar masses, and an initial composition: X = 0.7, Z == 0.03. Carbon depletion was unimportant in the 0.8 and 1.5 solar mass models. ln the 3 solar mass model the carbon to nitrogen ratio decreased to 1:200 within the main- sequence lifetime of that model. A large carbon depletion was also obtained in the models of 5, 7, and 10 solar masses. In the models of 15, 30, and 60 solar masses carbon depletion was unimportant. (IAA)

• Research Organization: Inst. of Astronomy, Warsaw
• NSA Number: NSA-29-027493
• OSTI ID: 4325330
• Journal Information: Acta Astron., v. 23, no. 3, pp. 191-196, Journal Name: Acta Astron., v. 23, no. 3, pp. 191-196; ISSN AASWA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*CARBON-- MAIN SEQUENCE STARS
*MAIN SEQUENCE STARS-- CHEMICAL COMPOSITION
*NITROGEN-- MAIN SEQUENCE STARS
ABUNDANCE
MASS
N56200* --Physics (Astrophysics & Cosmology)--Stars
STAR EVOLUTION
STELLAR ATMOSPHERES