How Bright are Manticore A & B?

Louis R wrote:Quite true, but there are reasons to suspect that this isn't a normal system. The outer planetary orbits shouldn't be stable, and the spectral classes and masses given suggest that there's a several-billion year difference in the ages of the stars.

ThinksMarkedly wrote:I agree on the orbits of the outer planets, but why are you saying that the stars can't have roughly the same age? Nothing prevents a G0/G2 pair, so you must be thinking of some more information.

Were the masses of the two stars ever given, not just their spectral classes? Or are you calculating that from the Manticore and Gryphon year lengths and their orbital radii?

House of Steel gives both the masses and the spectral class: A is a G0 with 1.12 Solar mass and B is a G2 with 0.92 Solar mass.

That's what they say, but for stars the sun's age the classes don't match the masses. I'd need to hunt down some good evolutionary tracks to get it fairly close, but off the top of my head B should be somewhere in the 6-8Ga range, but if A were that old it would be up around F6 or F7 if it was still on the main sequence - or possibly already G0IV, not G0V. Either way, _much_ more luminous than the sun, enough so that Manticore and Sphinx would be fried by now.

And while TM is right that there's nothing in principle preventing the formation of a G0/G2 binary - and in fact there are more than a few of them - it seems that the typical partition of a collapsing cloud leaves mass differences more like .5 - 1 Msol in the components. Which in this mass range makes for a substantial difference in spectral class. B0/B2 binaries are actually more common, normalized to the frequency of stars in that mass range.

tlb wrote:

ThinksMarkedly wrote:I agree on the orbits of the outer planets, but why are you saying that the stars can't have roughly the same age? Nothing prevents a G0/G2 pair, so you must be thinking of some more information.

Were the masses of the two stars ever given, not just their spectral classes? Or are you calculating that from the Manticore and Gryphon year lengths and their orbital radii?

House of Steel gives both the masses and the spectral class: A is a G0 with 1.12 Solar mass and B is a G2 with 0.92 Solar mass.