Planetary system around metal-poor star HIP 11952

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Planetary system around metal-poor star HIP 11952

Post by Lazarus on 9th March 2012, 8:22 pm

Planetary companions around the metal-poor star HIP 11952

A planetary system around an [Fe/H]=-1.9 star with giant planets in 7-day and 290-day orbits.
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Re: Planetary system around metal-poor star HIP 11952

Post by Edasich on 10th March 2012, 4:42 am

Nice find Very Happy
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Re: Planetary system around metal-poor star HIP 11952

Post by Lazarus on 15th March 2012, 5:13 pm

Odd that EPE hasn't picked this one up yet though.
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Re: Planetary system around metal-poor star HIP 11952

Post by Edasich on 16th March 2012, 7:17 am

Lazarus wrote:Odd that EPE hasn't picked this one up yet though.

Done. Updated rabbit

http://exoplanet.eu/star.php?st=HIP+11952
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Re: Planetary system around metal-poor star HIP 11952

Post by Baltazar on 28th March 2012, 5:01 am

This is absolutely ridiculous.

How can a F2V star be 12.8 billion years old?

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Re: Planetary system around metal-poor star HIP 11952

Post by Sirius_Alpha on 28th March 2012, 7:19 am

Presumably, such low metallicity will slow the fusion rate and prolong the life of the star, but I don't really know if that could keep it alive for upwards of 10 Gyr.

Lazarus?

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Re: Planetary system around metal-poor star HIP 11952

Post by Baltazar on 28th March 2012, 9:55 am

Even if what you propose its true, I'd hardly give it 7-8 billion years, let alone 10 billion years.

The problem is that the star seems to be not even near the end of its cycle, considering its still in a main sequence stage. I don't think the low metallicity plays such a major role in a long stellar lifespan for its type.

This is going to fuck up the current stellar evolutionary models we have.
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Re: Planetary system around metal-poor star HIP 11952

Post by Neuron on 28th March 2012, 10:27 am

Stars get hotter and brighter right before they expand to red giants so this might be a former late G type star near the end of its main sequence life.

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Re: Planetary system around metal-poor star HIP 11952

Post by Baltazar on 28th March 2012, 12:15 pm

Neuron wrote:Stars get hotter and brighter right before they expand to red giants so this might be a former late G type star near the end of its main sequence life.

I thought they just grow in read giants without any other alterations in their spectrallicity?
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Re: Planetary system around metal-poor star HIP 11952

Post by Sirius_Alpha on 28th March 2012, 12:30 pm

Baltazar wrote:I thought they just grow in red giants without any other alterations in their spectrallicity?

Turning into a red giant is, by defintion, a change in their spectral type. If I'm not mistaken, a star will get hotter until the helium flash, then it will expand and cool significantly (the red giant phase).

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Re: Planetary system around metal-poor star HIP 11952

Post by Baltazar on 28th March 2012, 1:55 pm

Sirius_Alpha wrote:Turning into a red giant is, by defintion, a change in their spectral type. If I'm not mistaken, a star will get hotter until the helium flash, then it will expand and cool significantly (the red giant phase).

Oh, okay. Didn't know that.

But I did say, "any other changes in spectra" Smile - implying becoming red giant is a spectral change as well.
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Re: Planetary system around metal-poor star HIP 11952

Post by Lazarus on 29th March 2012, 2:52 am

For a given stellar mass the lower metallicity will result in higher temperatures, and shorter stellar lifetime. From the paper:

Based on the surface gravity and radius derived from our analysis and the available literature data, HIP 11952 is more likely a star already evolved off the main-sequence, roughly sitting at the base of the subgiant branch.

Mass of the star is about 0.86 solar masses, playing around with the Y2 isochrones does suggest that the evolution of such a star at low metallicity can end up with a subgiant of similar temperature to HIP 11952 at ages around 11-12 Gyr or so.
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Re: Planetary system around metal-poor star HIP 11952

Post by Sirius_Alpha on 31st March 2012, 8:10 am

Lazarus wrote:For a given stellar mass the lower metallicity will result in higher temperatures, and shorter stellar lifetime.
Is this opposite for fully convective stars? I recall it being mentioned that higher metallicity encourages deuterium fusion at lower masses in brown dwarfs. Do I remember that wrong? Somewhere, I'm confused about what role metallicity plays in the fusion of the star.

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Re: Planetary system around metal-poor star HIP 11952

Post by marasama on 1st April 2012, 6:13 pm

I read information before on something like that.
http://solar-flux.forumandco.com/t51-planetary-masses-3rd-attempt

Brown Dwarf
if [Fe/H] > 0, then ~13 to ~65Mj
if [Fe/H] = 0, then ~13 to ~80Mj
if [Fe/H] < 0, then ~13 to ~80-90Mj

But my post was made back in 2008, so don't know if data has changed.

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Re: Planetary system around metal-poor star HIP 11952

Post by Sirius_Alpha on 20th August 2012, 8:21 pm

On arXiv now.
http://arxiv.org/abs/1208.4000

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Re: Planetary system around metal-poor star HIP 11952

Post by Borislav on 23rd January 2013, 9:14 am

Closed.

http://twiki.oats.inaf.it/twiki/pub/GAPS/HIP11952/hip11952v1.pdf

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Re: Planetary system around metal-poor star HIP 11952

Post by Edasich on 23rd January 2013, 10:50 am

It seems an incomplete research paper through, if not in progress.
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Re: Planetary system around metal-poor star HIP 11952

Post by Sirius_Alpha on 13th February 2013, 9:17 pm

Now on arXiv.
http://arxiv.org/abs/1302.3093

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Re: Planetary system around metal-poor star HIP 11952

Post by tommi59 on 14th February 2013, 7:45 am

Strange as I can understand that in case of low mass planets (gj 581 g,f) it could happen but 2 jovian planets was announced and now disproven
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Re: Planetary system around metal-poor star HIP 11952

Post by Edasich on 14th February 2013, 9:58 am

Moreover I don't get why only HIP 11952 c has been removed by EPE list...

How is that website working? :?
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Re: Planetary system around metal-poor star HIP 11952

Post by Lazarus on 14th February 2013, 3:16 pm

tommi59 wrote:Strange as I can understand that in case of low mass planets (gj 581 g,f) it could happen but 2 jovian planets was announced and now disproven
The paper mentions that the RV errors are quite high due to the star's relatively hot temperature and lack of metals. Maybe that had something to do with it?
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Re: Planetary system around metal-poor star HIP 11952

Post by Sirius_Alpha on 14th February 2013, 4:52 pm

I can't say I'm surprised. I know it's wholly unscientific, but looking at the RV plot for HIP 11952 in the original discovery paper, the fit didn't seem too convincing to me. It kinda looked as if it wasn't statistically significant.

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Re: Planetary system around metal-poor star HIP 11952

Post by Lazarus on 15th February 2013, 2:07 pm

Anyone tried the original velocity set in Systemic?
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Re: Planetary system around metal-poor star HIP 11952

Post by Sirius_Alpha on 15th February 2013, 2:30 pm

I can't get Systemic to work anymore :\

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Re: Planetary system around metal-poor star HIP 11952

Post by Edasich on 16th February 2013, 9:55 am

Sirius_Alpha wrote:I can't get Systemic to work anymore :\

Neither can I. The old version worked perfectly: the newest one crashes at once. Suspect
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Re: Planetary system around metal-poor star HIP 11952

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