Comments on: Another Close Binary, Another Big Planet

By: StevoR

StevoR — Wed, 28 Nov 2007 05:51:40 +0000

Thanks for the link to the actual paper too – interestingly from there :

The star HD196885 A or HIP 101966 (& why, oh why can’t we give notable stars like this one proper rather than just ctalogue names, could I suggest Farsuntu {“far-sun-too”}, Antisoluranstar (Rivial of Sun + Uranus-distance star) or at least just Hip-101 for short!)

- has a visual magnitude of 6.3 making it potentially just visible to the unaided eye in very dark skies.

- Is listed as luminosity class IV or sub-giant although this is confused by llisting it later as luminosity class V or main-sequence too. This makes it a bit like Procyon the nearest F-type star which is also variously termed a main-sequence dwarf or evolving sub-giant star …

(BTW. Luminosity classes : I = Supergiants, II & III = giants, IV = sub-giants, V = main sequence dwarfs VI = sub-dwarf, VII =white dwarfs.)

- is located 33 parsecs away (& please for the sake of making astronomy more accessible can we please note distances in light years too?) which by my iffy calculations ( 1parsec = 3 ly aprox so 33 x 3 = 99) is about 100 light years away.

A little far to be among the first stars visited unfortunately but still a fascinating system desrreving of more study.

- There are a lot of calculations and jargon but it seems there wasn’t aplnate where they thought and was this planet where they didn’t think from earlier studies … So perhaps this needs a bit of followup study although clearly a considerable amount of work has been put into by the team that did find this planet & they deserve our congrats & respect. They certainly have mine.

By: StevoR

StevoR — Wed, 28 Nov 2007 05:18:00 +0000

Thanks for that – great news article and a very interesting planetary system.

If the exoplanet has large enough moons could they be habitable -its twice as far out round a star two-&-a-half times as bright so an intriguing prospect ..

Seen from the planet (or its hypothetical if likely moons)the red dwarf would be relatively bright but not overpoweeringly so wouldn’t it?

Any idea on the liklihood of other planets – maybe rocky low-mass planets orbiting it as well – possibly in the habitable zone which I think would be larger for this brighter star?

I’m not sure how far this star is from us but it sounds like a system worth well investigating ..

By: andy

andy — Sun, 25 Nov 2007 10:59:03 +0000

I wonder how much the orbit of the planet would expand when the primary star loses mass during the red giant stage – far enough that it would enter the region where its orbit would be destabilised by the companion star?

By: Adam

Adam — Sun, 25 Nov 2007 00:56:57 +0000

Kudos. We might be too myopic with our thinking. Just look how much Hubble has captured in the far reaches of space.

Opportunities abound once craft actually able to reach the far regions of space.

Otherwise, keep exploring…..

By: Richard B. Drumm

Richard B. Drumm — Fri, 23 Nov 2007 05:02:46 +0000

This red dwarf at 17AU is almost as far from its “big sister” star as Uranus is from our sun. Even though it certainly outweighs Jupiter, it clearly doesn’t prevent other planets from forming around the big sister. I’m sure it has an effect on the planetary orbits like Jupiter has here. Little sister’s orbit is probably fairly circular, if it was very eccentric it’d probably prevent any planets from forming. So it probably won’t have an opportunity to steal any atmosphere from big sister when she goes into the red giant phase.

I wonder if little sister has any planets… Wouldn’t surprise me a bit.
-SERIOUSLY COOL-
Rich

By: Freiddie

Freiddie — Thu, 22 Nov 2007 09:25:32 +0000

This is amazing… Quite an unlikely place to find a planet. But I thought 3-body systems are supposed to be unstable, so does that mean the orbit is likely to change over time?