Quote:
Originally Posted by sjastro
If Sirius B was gaining mass at the expense of Sirius A, the centre of mass would be moving towards Sirius B and hence the orbital period of Sirius B would decrease. All of this however is very long term.
I imagine if mass is spiraling into Sirius B, then Sirius B should be an irregular variable.
Steven
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True...but given the separation of the two (around 20 AU) I can't see anything happening somehow (thankfully!!!!)
If Sirius was losing mass to the WD, the most likely outcome would be we'd have a recurrent nova in the system. Pretty spectacular from 8.6ly away, but we'd be relatively safe...a lot safer than if it really went pop!!!.
Where Type I's normally occur is in binary systems where one of the stars has filled its Roche Lobe (i.e. it's a red giant/supergiant itself) and the WD is sucking gas from a weakly held surface. In systems where the star is a normal MS star (rare), the WD is orbiting almost on top of the primary, so its tidal disturbances of the star are ripping gas off the surface.