On the Evolution of BM Orionis
Abstract: BM Orionis, an
eclipsing binary system which is located in the center of Orion Nebula Cluster,
posseses several enigmatic problems. Its intrinsic nature and nebular
environment make it harder to measure the physical parameters of the system,
but it is believed as an Algol-type binary, where the secondary component is a
pre-main sequence star with larger radius. To
assure this, several stellar models (M1 = 5.9 M and M2 = 2.0 M) are created
and simulated using MESA. Compared to non-rotating ones, models with rigid
rotation of i = 10-8 rad/s exhibit considerably similar properties during
pre-main sequence stage. However, 2.0 M star at assumed age of ~106 years is
6.46 times dimmer than the observed secondary star. There must be an external
mechanism to fill this luminosity gap. Then, simulated post-main sequence
binary evolution of BM Orionis that involves mass transfer shows that primary
star will reach helium sequence with the mass of ~0.9 M before second stage
mass transfer.
Author: Rhorom Priyatikanto
Journal Code: jpfisikagg130001
