5 new Exoplanets!

[Arch2008]

http://planetquest.jpl.nasa.gov/atlas/atlas_search.cfm?&Sort=DiscDate&SortDir=DESC

 

FYI, five new exoplanets were posted today, for a total of 19 so far this year.

[Widdekind]

Thanks for the reference !

 

 

GENERAL QUESTION: If Pulsars can sport "secondary planets" (born post-explosion), have Exoplanets similarly been seen orbiting White Dwarves ??

[CaptainPanic]

GENERAL QUESTION: If Pulsars can sport "secondary planets" (born post-explosion), have Exoplanets similarly been seen orbiting White Dwarves ??

White dwarves remain after a star expanded to a red giant. This means that any planet close to the star will likely be destroyed by the expanding star.

 

Most planets are discovered due to changes in the star's position, light intensity or wavelength. White dwarves simply aren't very bright, so possibly that makes detection difficult. In addition, as mentioned before, all planets will be at significant distance, and therefore changes observed in the star's position, light intensity or wavelength will be slow and may go undetected.

 

But maybe an expert can add some useful information - I'm certainly not an expert

[Arch2008]

Well I am certainly not an expert, but I’ll do my best to get the discussion started.

Secondary planets refer to planets formed by the debris of a stellar explosion.

http://www.astronomy.com/asy/default.aspx?c=a&id=8291

The first planets are blasted to rubble and the debris that does not reach escape velocity from the resulting neutron star forms a disk. This dusty disk can coalesce into secondary planets as seems to be the case with the planetary system of PSR 1257.

 

So are debris disks formed when a star evolves to white dwarf stage?

 

http://eis.jpl.nasa.gov/planetquest/TPF-I/evolutionCosmicRecycling.cfm

“Recently, the Spitzer Space Telescope had detected infrared excess emission from about 15 to 20% of old white dwarf stars near the Sun (Reach et al. 2006; Mullally et al. 2006). This emission indicates the presence of debris disks consisting of mostly large-solid particles that have resisted being dragged into the central white dwarf by the Poynting-Robertson drag for the age of the white dwarf. Such debris disks surrounding aging white dwarfs may trace the remnants of planetary systems that were destroyed during the post-main-sequence red-giant phase of their parent stars.”

 

One could argue that such disks might also merge through collisions into secondary planets. A recent article in Astronomy magazine discusses such a possibility. These planets would supposedly be carbon rich worlds like Titan. However, I know of no evidence that such secondary planets have actually been discovered.

 

(My 100th post, woohoo!)

Edited June 19, 2009 by Arch2008

[Martin]

Secondary planets refer to planets formed by the debris of a stellar explosion.

http://www.astronomy.com/asy/default.aspx?c=a&id=8291

The first planets are blasted to rubble and the debris that does not reach escape velocity from the resulting neutron star forms a disk. This dusty disk can coalesce into secondary planets as seems to be the case with the planetary system of PSR 1257.

 

So are debris disks formed when a star evolves to white dwarf stage?

 

http://eis.jpl.nasa.gov/planetquest/TPF-I/evolutionCosmicRecycling.cfm

“Recently, the Spitzer Space Telescope had detected infrared excess emission from about 15 to 20% of old white dwarf stars near the Sun (Reach et al. 2006; Mullally et al. 2006). This emission indicates the presence of debris disks consisting of mostly large-solid particles that have resisted being dragged into the central white dwarf by the Poynting-Robertson drag for the age of the white dwarf. Such debris disks surrounding aging white dwarfs may trace the remnants of planetary systems that were destroyed during the post-main-sequence red-giant phase of their parent stars.”

 

One could argue that such disks might also merge through collisions into secondary planets. A recent article in Astronomy magazine discusses such a possibility. These planets would supposedly be carbon rich worlds like Titan. However, I know of no evidence that such secondary planets have actually been discovered.

 

(My 100th post, woohoo!)

 

Great post, thanks for starting such an informative thread. Other posters who haven't tried this may be interested that the JPL catalog you pointed us to has some nice features where you can narrow and manipulate the list just by putting a check in a box. Here it is narrowed to terrestrial exos.

 

http://planetquest.jpl.nasa.gov/atlas/atlas_search.cfm?Planet_Type=Terr&Sort=DiscDate&SortDir=DESC

 

I defer to your knowledge of exoplanets so correct or amend what I say about this---I assume that a pulsar planet wouild be found by wobble, measured very accurately by the doppler of the pulsar signal.

 

Most exoplanets are, I believe, found by wobble detected by the doppler shift of spectral lines in the star's light which I suppose is a lot more difficult than measuring it with a pulsar radio signal. A planet around a white dwarf (re: Widdy's question) would be more difficult to detect by wobble. I did some poking around on the web and could not find any indications that a white dwarf with planet had been found. But I couldn't exclude it, based on what I found. Maybe someone else will find something more conclusive.

Edited June 19, 2009 by Martin

[Arch2008]

You are most welcome, Martin. I usually check the Planetquest site, so you can imagine my surprise at the addition of so many planets on one day. I thought that they might have been discovered by the Kepler mission, but apparently not. I found one paper from the discovering team of some of the planets and they didn’t mention Kepler.

http://xxx.lanl.gov/abs/0906.1804

(Which Widdekind may find interesting)

As you may have noticed, BD20 2457 b and c are quite large. They are arguably brown dwarfs and not planets at all. I suppose that they are large enough to have caused a “wobble” in their parent star.

[Arch2008]

FYI, four more exoplanets were posted today. Again, these seem to have been found without the aid of Kepler.

 

http://planetquest.jpl.nasa.gov/atlas/atlas_search.cfm?&Sort=DiscDate&SortDir=DESC

[Airbrush]

Any volunteers for a one-way mission to Gliese 581 at only 20.5 ly?

[Sisyphus]

Any volunteers for a one-way mission to Gliese 581 at only 20.5 ly?

 

At 20.5 ly, it would be quite a bit less than one-way.

[Martin]

FYI, four more exoplanets were posted today. Again, these seem to have been found without the aid of Kepler.

 

http://planetquest.jpl.nasa.gov/atlas/atlas_search.cfm?&Sort=DiscDate&SortDir=DESC

 

Thanks again for relaying this news! Having an alert lookout report like this is great.

I saw a July 6, 2009 news bulletin

http://planetquest.jpl.nasa.gov/news/roundUp.cfm

but I'm not sure it covered the four you mentioned.

Do you have links to any more descriptive info?

[Arch2008]

Unfortunately, not yet Martin. We're having a lot of electrical storms in Ohio today. Maybe tomorrow.

 

Spoke too soon. I have found this. Apparently HD16760 b is one of the Habitable Zone alumni of Exoplanets.

http://www.planetarybiology.com/hz_candidates/

 

If you click the "Home" link in the upper left corner of the page, this seems to be a really interesting site.

Edited August 4, 2009 by Arch2008

[stephengor]

All five of these planet-bearing stars are metal-rich, with [Fe/H]>+0.27, reinforcing the strong correlation between planet occurrence and metallicity. From the full sample of 1330 stars monitored at Keck, Lick, and the Anglo-Australian Telescope, the shortest orbital period for any planet is 2.64 days, showing that shorter periods occur less frequently than 0.1% in the solar neighborhood. Photometric observations were acquired for four of the five host stars with an automatic telescope at Fairborn Observatory. The lack of brightness variations in phase with the radial velocities supports planetary-reflex motion as the cause of the velocity variations. No transits were observed, but their occurrence is not ruled out by our observations.

 

Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the University of California and the California Institute of Technology. Keck time has been granted by both NASA and the University of California.

[Arch2008]

Four new Exoplanet's for August. One is only .08 Jupiter mass, so Earth sized exo's may be posted soon. Go Kepler!

http://planetquest.jpl.nasa.gov/atlas/atlas_search.cfm?&Sort=DiscDate&SortDir=DESC

It seems that two of these may be in the habitable zone of their stars, but the Planetary Biology site has not been updated yet, so I will reserve judgement.

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Two more were added in the last few hours. 6 in one day!

 

P.S. Planetary Biology lists 373 exo's now, not 363, so perhaps NASA must catch up.

http://www.planetarybiology.com/exoexplorer_planets/

Edited August 27, 2009 by Arch2008
Consecutive posts merged.

[Arch2008]

This story caught my eye:

http://news.yahoo.com/s/ap/20091019/ap_on_sc/us_sci_new_planets

Nothing has been posted at Planetquest yet, so no data.

I did find this:

http://www.eso.org/public/outreach/press-rel/pr-2009/pr-39-09.html

Edited October 19, 2009 by Arch2008

[Airbrush]

Anyone know when the Kepler Mission will start reporting results?

[Arch2008]

Here is the Kepler mission site:

http://kepler.nasa.gov/about/news.html

 

Supposedly by next year they will start releasing results.

[Arch2008]

The wait is over:

http://www.nasa.gov/mission_pages/kepler/news/kepler-5-exoplanets.html

 

Deja vu, 5 new exoplanets!

[CaptainPanic]

Ok, I didn't read a lot of literature on this - so my question may be a n00b question - but did the NASA researchers calibrate their Kepler telescope on stars known to have planets, or are they just assuming that the new observations are correct?

 

You'd expect that the first observed planets would be known planets.

[Arch2008]

No, these are new exoplanets that were confirmed by ground observatories after Kepler detected them.

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P.S. Eight more exoplanets from sources other than Kepler were added today.

http://planetquest.jpl.nasa.gov/atlas/atlas_search.cfm?&Sort=DiscDate&SortDir=DESC

[Airbrush]

"...the Kepler mission continuously and simultaneously observes more than 150,000 stars." and it will do that for 3 years. So they must keep track of each of the individual stars in question over a period of years. Tough record keeping.

 

"did the NASA researchers calibrate their Kepler telescope on stars known to have planets...?"

 

No, they are observing all the stars in a dense region of the habitable zone of the Milky Way. Kepler is looking for the first signs of possible planets.