Defining the Termination of the Asymptotic Giant Branch

Details Defining the Termination of the Asymptotic Giant Branch Defining the Termination of the Asymptotic Giant Branch

2007-12-22

arxiv.org/abs/0712.3835v1

Astronomy and Astrophysics

Astrophysics

Submitted to ApJ Letters

Scientific paper

10.1086/528987

I suggest a theoretical quantitative definition for the termination of the asymptotic giant branch (AGB) phase and the beginning of the post-AGB phase. I suggest that the transition will be taken to occur when the ratio of the dynamical time scale to the the envelope thermal time scale, Q, reaches its maximum value. Time average values are used for the different quantities, as the criterion does not refer to the short time-scale variations occurring on the AGB and post-AGB, e.g., thermal pulses (helium shell flashes) and magnetic activity. Along the entire AGB the value of Q increases, even when the star starts to contract. Only when a rapid contraction starts does the value of Q start to decrease. This criterion captures the essence of the transition from the AGB to the post AGB phase, because Q is connected to the stellar effective temperature, reaching its maximum value at T~4000-6000 K, it is related to the mass loss properties, and it reaches its maximum value when rapid contraction starts and envelope mass is very low.

Affiliated with

Also associated with

No associations

Rating

Defining the Termination of the Asymptotic Giant Branch does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Defining the Termination of the Asymptotic Giant Branch, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Defining the Termination of the Asymptotic Giant Branch will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-425811