Two new super-earths: 61 Vir and HD1461 !!

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Two new super-earths: 61 Vir and HD1461 !!

Post by exoplanet on 14th December 2009, 1:42 pm

http://www.universetoday.com/2009/12/14/first-super-earths-discovered-around-sun-like-stars/#more-47538

cheers santa

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Edasich on 14th December 2009, 2:28 pm

Merry christmas to us all!! What a discovery! Very Happy

http://www.phys.unsw.edu.au/~cgt/planet/AAPS_Home.html

3 Planet system at 61 Virginis?? *faints*


Last edited by Edasich on 14th December 2009, 2:46 pm; edited 2 times in total
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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Sirius_Alpha on 14th December 2009, 2:38 pm

If I'm reading this right, hints of one or two more planets at HD 1461 as well. This is exciting!

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Edasich on 14th December 2009, 2:46 pm

Papers 4 UUUUUU.... *lol* =p

http://www.phys.unsw.edu.au/~cgt/press/Vogt2009.pdf

http://www.phys.unsw.edu.au/~cgt/press/Jones2009.pdf
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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Sirius_Alpha on 14th December 2009, 2:58 pm

And what's more, they're publicly available.
http://www.phys.unsw.edu.au/~cgt/planet/AAPS_Home.html

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by exofever on 14th December 2009, 3:18 pm

HARPS team probably scooped. They have been observing 61 Vir and HD1461 a lot. I hope this will inspire them to divulge their data sooner rather than later.

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Edasich on 14th December 2009, 3:19 pm

I only complain about HD 1461 b,c,d being not yet announced
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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Sirius_Alpha on 14th December 2009, 3:24 pm

exofever wrote:HARPS team probably scooped. They have been observing 61 Vir and HD1461 a lot. I hope this will inspire them to divulge their data sooner rather than later.
Ouch, good point. I'm pretty sure 61 Vir was in their GTO programme, I don't recall if HD 1461 was or not =s.

Edasich wrote:I only complain about HD 1461 b,c,d being not yet announced
Yeah what's up with that?

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Edasich on 14th December 2009, 3:29 pm

Sirius_Alpha wrote:
exofever wrote:HARPS team probably scooped. They have been observing 61 Vir and HD1461 a lot. I hope this will inspire them to divulge their data sooner rather than later.
Ouch, good point. I'm pretty sure 61 Vir was in their GTO programme, I don't recall if HD 1461 was or not =s.

Edasich wrote:I only complain about HD 1461 b,c,d being not yet announced
Yeah what's up with that?

Oh oh! Shame on HARPS!! Yes , I think HD 1461 were in GTO sample too.

I don't know. Maybe lively worlds...?
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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Sirius_Alpha on 14th December 2009, 3:32 pm

I'm sure we'll know something more when the arXiv updates tonight.

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Edasich on 14th December 2009, 3:51 pm

Let's all cross finger. December is turning out a hot month for exoplanets.
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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by exoplanet on 14th December 2009, 4:08 pm

The Harps GTO catalogue:

http://www.astro.up.pt/~sousasag/harps_gto_catalogue.html

HD 1461 is there.

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Lazarus on 14th December 2009, 4:16 pm

systemic has the HD 1461 paper.
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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Sirius_Alpha on 14th December 2009, 4:18 pm

Thanks for that, Lazarus. Somehow I missed it when reading that post.

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Lazarus on 14th December 2009, 6:01 pm

So these are the first low mass planetary systems orbiting stars in the temperature range where the lithium-planets anticorrelation occurs. Both appear to have low lithium abundances:

61 Virginis: A(Li) < 0.86
HD 1461: A(Li) < 1.04
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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Borislav on 14th December 2009, 6:26 pm

Fantastic! Three unique systems in one day! California group, congratulations! About 61 Virgin could guess at ESO archive on huge number of measurements on HARSP. Perhaps there is more planets ...

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by lodp on 14th December 2009, 9:22 pm

Yep its up on arXiv!!!! Yeah!

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Sirius_Alpha on 15th December 2009, 1:55 am

Borislav wrote:Perhaps there is more planets ...

According to the paper, there are hints of a fourth planet. It reduces the rms, but isn't too statistically significant. It is written that they will continue to monitor the star to resolve the issue, as well as constrain the eccentricities of the three planets.

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Borislav on 15th December 2009, 2:34 am


We note that the habitable zone of 61 Vir is located in the vicinity of a 300-day orbit. At this separation from the parent star, a 2
MEath planet induces a RV semi-amplitude K = 0.2 ms1 . Assuming a combined stellar jitter and median internal uncertainty of 1.5 ms1 , this is a factor of about 30 greater than the 0.05 ms1 precision required to make a 4 sigma measurement of a such a small signal. If precision scales as the square root of the total number of Doppler measurements, a total of 30^2 or 900 velocities (an additional 700 more) would allow for the detection of such a planet with a S/N of 4.

Perhaps combining data of the Californian and the Geneva group will get a very deep limits on the habitable zone.

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Borislav on 15th December 2009, 7:15 am

About three years ago was about a similar situation.
http://arxiv.org/abs/astro-ph/0608279v1 14 Aug 2006
http://arxiv.org/abs/astro-ph/0608396 18 Aug 2006
The difference then 4 days!

I wonder how long it will take place between the publication of the California and the Geneva group of planetary solutions in 61 Virgin? Two or three days, a week or two weeks before the New Year?

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Edasich on 15th December 2009, 9:14 am

Putting RV sets in Systemic, I find a strong signal of 352.026 days hinting a 0.05 jupiter masses planet. A bit massive for an Earth-like ones.

However more RV sets would be required as they state.
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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Lazarus on 15th December 2009, 1:50 pm

Regarding the 352-day period, this appears to be to do with the window function (i.e. the periods you see as a result of the sampling)... on page 11 of Vogt et al. (2009):

This P = 38.13-day signal, furthermore, lies far from the periods favored by the sampling window (Figure 3, bottom panel), which produces spurious power at periods near 357, 191, 95.5, 652, 29.6, and 110 days. (Signals near these periods would naturally attract suspicion as being artifacts of the lunar and yearly periods on telescope scheduling.)
(emphasis mine)
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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by AVBursch on 18th December 2009, 10:30 am

There is still the debris disk that was recently imaged by Spitzer, which goes from 96 au to 195 au. If the disk has a well defined inner edge like the one around Fomalhaut, then one can possibly infer the existence of an additional planet with a semi-major axis of 90 au. Such a world, if it exists, would be at least 40 - 60 times the mass of Earth. Unfortunately, directly imaging the planet could be problematic -- 61 Virginis is much older than either Fomalhaut or HR 8799, which means that even a planet several times more massive than Jupiter would be undetectable.

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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by Lazarus on 18th December 2009, 3:21 pm

According to the 61 Virginis planets discovery paper, an improved model of the debris disk which assumes it is composed of 0.25Ám silicate grains puts the inner edge at 120▒20 AU and the outer edge at 220▒10 AU.
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Re: Two new super-earths: 61 Vir and HD1461 !!

Post by exoplanet on 7th January 2010, 10:50 am

A week ago I published this e-mail interview I did with Paul Butler in a Portuguese blog about astronomy. There is a small preamble in portuguese but the interview is reproduced in the original english. Hope you enjoy it.

http://astropt.org/blog/2009/12/30/entrevista-com-paul-butler/

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Re: Two new super-earths: 61 Vir and HD1461 !!

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