Interesting extrasolar planet discoveries - Page 21

Hungry4info · #**601** (**permalink**) 18-September-2009, 03:09 AM

WASP-9 b has been retracted. Apparently, it turned out to be a triple-star system.
http://tamise.ujf-grenoble.fr/wws/ar.../msg00003.html

eburacum45 · #**602** (**permalink**) 04-October-2009, 09:24 PM

Corot-7b - a silicon monoxide atmosphere?
http://news-info.wustl.edu/news/page/normal/14753.html
The atmosphere has been simulated and appears very interesting.
From that article:

Quote:

"Perhaps because they were cooked off, COROT-7b's atmosphere has none of the volatile elements or compounds that make up Earth's atmosphere, such as water, nitrogen and carbon dioxide.
"The only atmosphere this object has is produced from vapor arising from hot molten silicates in a lava lake or lava ocean," Fegley says.
(snip)
" Sodium, potassium, silicon monoxide and then oxygen — either atomic or molecular oxygen — make up most of the atmosphere." But there are also smaller amounts of the other elements found in silicate rock, such as magnesium, aluminum, calcium and iron.
(snip)
...the exoplanet's atmosphere condenses out minerals such as enstatite, corundum, spinel, and wollastonite. In both cases the fractions fall out in order of
boiling point.
Elemental sodium and potassium, which have very low boiling points in comparison with rocks, do not rain out but would instead stay in the atmosphere, where they would form high gas clouds buffeted by the stellar wind from COROT-7. These large clouds may be detectable by Earth-based telescopes. The sodium, for example, should glow in the orange part of the spectrum, like a giant but very faint sodium vapor streetlamp. "

What a fantastic world!

Orion's Fan · #**603** (**permalink**) 04-October-2009, 11:15 PM

What is the approximate exoplanet count at the moment?

eburacum45 · #**604** (**permalink**) 04-October-2009, 11:39 PM

The Extrasolar Encyclopedia says 374.
http://exoplanet.eu/
That may not take into account the retraction of WASP-9 b.

Orion's Fan · #**605** (**permalink**) 06-October-2009, 04:44 PM

Quote:

Originally Posted by eburacum45

The Extrasolar Encyclopedia says 374.
http://exoplanet.eu/
That may not take into account the retraction of WASP-9 b.

Thanks for that link.

timb · #**606** (**permalink**) 19-October-2009, 01:06 PM

29 new planets and 3 brown dwarfs presented by Stephane Udry and Xavier Bonfils at the Porto Conference "Towards Other Earths: perspectives and limitations in the ELT era" 19 Oct 2009.

Data from Udry:

Code:

Id              SP     [Fe/H]   log(R'_HK)   Vsini     Prot     M1     P 	M     characteristic     Author
                                              [km/s]     [d]   [Msun]  [d] 	[MJ]
========       =====   ======   ==========   ======    =====  ======  ==== 	====   ==============     ======
HD5388          F6V     -.27     -4.98       4.24       -     1.21    777	1.96   e2, deficient     Santos et al.
HD181720        G1      -.53     -5.01       1.5        -     0.92    956	0.37   e4, deficient     Santos et al.
HD190984        F8V     -.48     -5.01       3.4        -     0.91    4885	3.10   e4, deficient     Santos et al.
-----------------------------------------------------------------------------------------------------------------------
HD6718          G0      -0.06    -4.97       1.76      26     0.96   2496	1.56   e2                 Naef et al.
HD8535          G0V      0.02    -4.95       1.41      13     1.13   1313	0.63   e2                 Naef et al.
HD28254         G5V      0.36    -5.10       2.50      37     1.06   1117	1.16   e2, e unconstr.    Naef et al.
HD290327        G5IV    -0.11    -4.96       1.44      36     0.90   2443	2.54   e2                 Naef et al.
HD43197         K0?      0.40    -5.06       2.18      44     0.96   327.8	0.60   e2                 Naef et al.
HD44219         G5       0.03    -5.03       2.22      31     1.00   472	0.58   e2, curved drift   Naef et al.
HD148156        G1V      0.29    -4.94       5.7       14     1.22   1010	0.91   e2, curved drift   Naef et al.
HD156411        F8      -0.12    -5.05       3.3       22     1.25   842	0.74   e2                 Naef et al.
HIP103019       K5      -0.30      -          -         -     0.70   917.6	52.6   e2, Brown Dwarf    Naef et al.
-----------------------------------------------------------------------------------------------------------------------
HIP5158 b       K5       0.10    -4.80       1.57      42     0.78   344	1.3    e2, curved drift   Lo Curto et al.
HD125612 b      G3V      0.23    -4.83       3.11      21     1.09	4.1547   0.067  e2, 3-pl system?   Lo Curto et al.
                         HD125612 b previuosly known: Fischer et al 2007	ApJ 669 1336-
          c                                                           551.8	3.1
          d                                                           4613	7,1
HD215497 b      K3V      0.23    -5.01       1.67      50     0.87   3.93	0.017  e2, 2pl-system     Lo Curto et al.
          c                                                           567	0.33
-----------------------------------------------------------------------------------------------------------------------
BD-082823 b     K3V     -0.07    -4.8        1.4       37     0.74   5.60	0.045  e2(+Hipp), 2pl     Hebrard et al.
           c                                                          237.6	0.33
-----------------------------------------------------------------------------------------------------------------------
HD85390         K1V     -0.07    -4.91       1.12      40.1   0.76   781	45.3   e1                 Mordasini et al.
HD90156         G5V     -0.24    -4.90       0.33      24.0   0.84   49.8	17.5   e1                 Mordasini et al.
HD103197 b      K1Vp     0.21    -5.05       1.68      47.8   0.90   7.76	5.06   e2                 Mordasini et al.
          c                                                           47.8	35.8
------------------------------------------------------------------------------------------------------------------------
HD9578          G1V      0.11     -4.66       1.64     12.3   1.12   494	0.62    e2, noisy, bis?    Segransan et al.
HD63765         G9V     -0.16     -4.75       1.63     26.0   0.86   356	0.69    e1, act, coralie   Segransan et al.
HD104067        K2V     -0.06     -4.78       1.61     36.9   0.79   55.8	0.16    e1, curved drift   Segransan et al.
HD125595        K4V      0.02     -4.82       1.5      40.8   0.76   9.67	0.045   e2, act            Segransan et al.
HIP70849        K7V       -         -         1.93      -     0.63   >3000	>5      e2, P poorly cons. Segransan et al.
------------------------------------------------------------------------------------------------------------------------

Data from Bonfils (papers by Forveille et al. and Delfosse et al., submitted):

Code:

GJ 433 b        M = 0.019 M_Jup  P =    7 days
GJ 667C b           0.018               7
HIP 12961 b         0.47               57
GJ 676A b           4                1000

Kullat Nunu · #**607** (**permalink**) 19-October-2009, 04:57 PM

BBC: Scientists announce planet bounty

Quote:

"From [our] results, we know now that at least 40% of solar-type stars have low-mass planets. This is really important because it means that low-mass planets are everywhere, basically," explained Stephane Udry from Geneva University, Switzerland.

Swift · #**608** (**permalink**) 19-October-2009, 08:46 PM

Quote:

Originally Posted by Kullat Nunu

BBC: Scientists announce planet bounty

Story on same work from Nature.com's blog.

Quote:

A huge haul of exoplanetary treasure has just been revealed. To those of you who’ve read more stories about exoplanets than you’ve had hot dinners, this news is unlikely to send you into throes of excitement. Neverthless, the haul of 32 new exoplanets announced by the HARPS (High Accuracy Radial Velocity Planet Searcher) team is significant.

The planets may not be the biggest, fattest, smallest or Earthiest, but they show that the chances of us finding Earth-like planets are pretty high. Stéphane Udry from the Geneva Observatory, who announced tha findings during a conference in Porto, Portugal, says that the HARPS results show that astronomers are going about this in the right way so far: “We know that close to 40% of solar-type stars have low mass planets. Low mass planets are everywhere, basically,” he says.

The search, done by the HARPS team on the European Southern Observatory’s 3.6 metre telescope at La Silla, in Chile’s Atacama desert, turned up two candidate planets that are six times the mass of Earth, and two planet candidates that are five times the mass of the Earth. The smallest exoplanet found so far was also by the HARPS team, and was about two Earth masses.

...

And there’s yet more to come. Udry says there’s the same again, if not more, waiting to be announced over the next year.

timb · #**609** (**permalink**) 19-October-2009, 09:22 PM

Quote:

Originally Posted by Kullat Nunu

BBC: Scientists announce planet bounty

Quote:

"From [our] results, we know now that at least 40% of solar-type stars have low-mass planets. This is really important because it means that low-mass planets are everywhere, basically," explained Stephane Udry from Geneva University, Switzerland.

What he means by "low-mass" isn't clear. By my count only 6 of the 27 host stars in the latest announcement hosts a planet less than 0.1 M_J. Maybe there's some statistical argument behind it that takes into account the detection probability.

Kullat Nunu · #**610** (**permalink**) 20-October-2009, 07:14 AM

Of course... Super-Earths are very hard to find, yet they have already found so many of them. Thus they should be common.

George · #**611** (**permalink**) 23-October-2009, 03:37 PM

The discovery trend is looking nice. 2009 is already a record at 72 so far (61 total for 2007).

Swift · #**612** (**permalink**) 23-October-2009, 03:48 PM

George,
I assume that graph is discoveries per year and not the cumulative. If so... wow!

George · #**613** (**permalink**) 23-October-2009, 08:10 PM

Quote:

Originally Posted by Swift

George,
I assume that graph is discoveries per year and not the cumulative. If so... wow!

Yep, they're annual discoveries.

This was predictable since technology advancements and big bucks would seek ways to hunt these babies down. [In fact, even I posted a exponential growth graph somewhere in this thread.

]

[The fit is conservative because I did not extrapolate to the end of this year, which may increase the 2009 amount significantly, at least enough to bump the growth rate.]

timb · #**614** (**permalink**) 24-October-2009, 08:10 AM

Quote:

Originally Posted by Kullat Nunu

Of course... Super-Earths are very hard to find, yet they have already found so many of them. Thus they should be common.

True, one might project that they are common, but he said know.

Hungry4info · #**615** (**permalink**) 24-October-2009, 08:50 AM

I found the graph a little hard to read. But fairly consistent with one at exoplanet.eu

George · #**616** (**permalink**) 24-October-2009, 07:36 PM

Nice! I must of miscounted the 2008 number. I moved the 1989 discovery to 2006 (updated year) because I don't think this was the official first exoplanet recognized. I think the first exoplanet may be 51 Peg b, which wasn't till 1995, so the Exoplanet Encyclopedia may eventually get changed for credit purposes someday. I don't know how that works, but I'm guessing a change may come.

These early years do not have that much bearing on the trend that I find wonderful.

Kullat Nunu · #**617** (**permalink**) 25-October-2009, 09:05 AM

Quote:

Originally Posted by timb

True, one might project that they are common, but he said know.

In that case he knows something we don't

. They told there's lots of planets not yet published.

Romanus · #**618** (**permalink**) 25-October-2009, 03:16 PM

Wouldn't be surprised to see those totals go well over 100 a year once COROT and Kepler data start coming out in force.

A few years ago, on a Space.com poll I voted for late 2011 being the year we hit an exoplanet count of 1000. Here's to hoping I was too cautious.

Ilya · #**619** (**permalink**) 25-October-2009, 07:29 PM

Quote:

Originally Posted by Hungry4info

I found the graph a little hard to read. But fairly consistent with one at exoplanet.eu

What is the 1 discovery in 1989??

Hot Sexy Jupiter · #**620** (**permalink**) 31-October-2009, 08:39 PM

Gamma Cephei Ab. Its existence was suspected in 1988/89 by two different teams, but not confirmed until much later (2002), so it doesn't usually get credited with being the first exoplanet discovered like the PSR 1257+12 planets found in 1992 do.

George · #**621** (**permalink**) 01-November-2009, 07:22 PM

I wonder what was the first observation that became explained by an actual exoplanet? Perhaps one of Leavitts variables, something from a binary study, or an earlier variance found for another pulsar mabye?

Doodler · #**622** (**permalink**) 08-November-2009, 06:53 PM

Quote:

Originally Posted by George

Nice! I must of miscounted the 2008 number. I moved the 1989 discovery to 2006 (updated year) because I don't think this was the official first exoplanet recognized. I think the first exoplanet may be 51 Peg b, which wasn't till 1995, so the Exoplanet Encyclopedia may eventually get changed for credit purposes someday. I don't know how that works, but I'm guessing a change may come.

These early years do not have that much bearing on the trend that I find wonderful.

The first officially recognized planets were a trio of pulsar planets discovered in 1992. 51 Peg b was the first around a main sequence star.

George · #**623** (**permalink**) 08-November-2009, 08:40 PM

Quote:

Originally Posted by Doodler

The first officially recognized planets were a trio of pulsar planets discovered in 1992. 51 Peg b was the first around a main sequence star.

IIRC, only one of the pulsars was verified to have a planet. Is this right?

Drunk Vegan · #**624** (**permalink**) 08-November-2009, 10:00 PM

Quote:

Originally Posted by George

IIRC, only one of the pulsars was verified to have a planet. Is this right?

Yes, but that pulsar was found to have three planets - one with a mass around the size of the Moon, the other approximately Earth sized, and the third about 3 times Earth mass, IIRC.

Bynaus · #**625** (**permalink**) 09-November-2009, 08:46 AM

One with a mass a bit higher than the Moon, the two others about 3.9 and 4.3 Earth masses. There is even a 0.4 Jupiter masses gas giant somewhat farther out in the system.

George · #**626** (**permalink**) 09-November-2009, 02:32 PM

Quote:

Originally Posted by Drunk Vegan

Yes, but that pulsar was found to have three planets - one with a mass around the size of the Moon, the other approximately Earth sized, and the third about 3 times Earth mass, IIRC.

Thanks to you and Bynaus for the info. It tickles me that our first is from a pulsar, of all places.

[I understand the data advantage, but why are they there?

]

Kullat Nunu · #**627** (**permalink**) 10-November-2009, 07:17 AM

Quote:

Originally Posted by Bynaus

One with a mass a bit higher than the Moon, the two others about 3.9 and 4.3 Earth masses. There is even a 0.4 Jupiter masses gas giant somewhat farther out in the system.

No, that planet was retracted some years ago. Instead, there seems to be an asteroid belt beyond the outermost planet, with hints of a Ceres-mass object.

GOURDHEAD · #**628** (**permalink**) 10-November-2009, 05:45 PM

Quote:

Originally Posted by George

Thanks to you and Bynaus for the info. It tickles me that our first is from a pulsar, of all places.

[I understand the data advantage, but why are they there?)]

My guess is that they formed early in the life of the star system and survived the supernova that produced the pulsar. The material that was expelled during the supernova explosion went by the planets so fast there was not time for the heat and erosion to completely grind them down. A lot depends on how variable and nova-like the star was prior to the supernova stage. Since Betelgeuse occupies a large volume in its current state, there probably won't be much left of any planets currently within its envelope after its supernova stage and that could be typical. Those more expert than I have suggested that the planets form from something similar to a planetary nebula after stabilization following the supernova.

Ilya · #**629** (**permalink**) 10-November-2009, 06:21 PM

Quote:

Originally Posted by GOURDHEAD

My guess is that they formed early in the life of the star system and survived the supernova that produced the pulsar. The material that was expelled during the supernova explosion went by the planets so fast there was not time for the heat and erosion to completely grind them down. A lot depends on how variable and nova-like the star was prior to the supernova stage. Since Betelgeuse occupies a large volume in its current state, there probably won't be much left of any planets currently within its envelope after its supernova stage and that could be typical. Those more expert than I have suggested that the planets form from something similar to a planetary nebula after stabilization following the supernova.

I am fairly certain a planetary system cannot survive a supernova explosion. Not because "heat and erosion would completely grind them down", but because the star loses so much mass in the process, anything in orbit around it would suddenly find itself with an escape velocity.

If the exploding star is a part of binary pair, things get more complicated, and some of the original planets might remain, but this is not the case with PSR 1257+12.

George · #**630** (**permalink**) 10-November-2009, 07:05 PM

There is also the view that they formed after the supernova, but I don't want to get into too much of this and distract from the thread topic.

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