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Blob
2006-May-18, 07:14 PM
Astronomers Use Innovative Technique to Find Extrasolar Planet


A planet transits an 11th magnitude, G1V star in the constellation Corna Borealis.
We designate the planet XO-1b, and the star, XO-1, also known as SC0241-01657. XO-1 lacks a trigonometric distance; we estimate it to be 200 20pc. Of the ten stars currently known to host extrasolar transiting planets, the star XO-1 is the most similar to the Sun its physical cartelistic: its radius is 1.00.8 solar radii:, its mass is 1.00.3 solar masses:, Vsini<3kms-1, and its metallicty (Fe/H. is 0.150.4) The orbital period of the planet XO-1b is 3.9415340.027 days, one of the longer ones known. The planetary mass is 0.90.7MJ, which is marginally larger than that other transiting planets with periods between 3 and 4 days. Both the planetary radius and the inclination are functions of the spectroscopicaly determined stellar radius. If the stellar radius is 1.00.8R, then the planetary radius is 1.300.1RJ and the inclination of the orbits 87.1.2


Read more (http://fr.arxiv.org/PS_cache/astro-ph/pdf/0605/0605414.pdf) (PDF)

Another link (http://hubblesite.org/newscenter/newsdesk/archive/releases/2006/22/)

ToSeek
2006-May-18, 09:05 PM
Astronomers Use Innovative Technique to Find Extrasolar Planet (http://hubblesite.org/newscenter/newsdesk/archive/releases/2006/22/)


An international team of professional and amateur astronomers, using simple off-the-shelf equipment to trawl the skies for planets outside our solar system, has hauled in its first "catch." The astronomers discovered a Jupiter-sized planet orbiting a Sun-like star 600 light-years from Earth in the constellation Corona Borealis. The team, led by Peter McCullough of the Space Telescope Science Institute in Baltimore, Md., includes four amateur astronomers from North America and Europe.

Blob
2006-May-19, 12:36 AM
Hum,
from Bruce Garys website...

"This web page describes contributions to the study of the XO-1 exoplanet system by observations with the Hereford Arizona Observatory 14-inch (Ed - MEADE ) amateur telescope during the 11 months preceding the Space Telescope Science Institute press release on May 18, 2006.
The goal is to encourage other amateurs to refine their observing and data analysis techniques so that they can contribute quality observations for use in the study of this interesting extra-solar system. A companion web page gives details of a successful transit observation on March 14, 2006 that I use for a "how to" case study tutorial. It illustrates my belief that the two most important considerations for achieving good exoplanet transit data are: 1) keep the star field fixed to the same location on the CCD chip for the entire observing session, and 2) use an R-filter."

The star XO-1 is located in the constellation Corona Borealis, at R.A. 16h 02m 11s.84 Dec. +28&#176; 10' 10".4

http://brucegary.net/X/x.htm

Van Rijn
2006-May-19, 12:47 AM
Here is the report (PDF) on that:

http://xxx.lanl.gov/PS_cache/astro-ph/pdf/0605/0605414.pdf

It amazes me that amateur astronomers as well as professionals using relatively simple hardware are starting to find exoplanets. Of course "relatively simple" today includes CCDs and sophisticated computers that would have amazed any astronomer just a few decades ago.

Edited to add:

I see there is another thread with this already:

http://www.bautforum.com/showthread.php?t=41660

sarongsong
2006-May-19, 12:56 AM
...Called the XO telescope (http://starbulletin.com/2006/05/19/news/art3b.jpg), it consists of two 200-millimeter telephoto camera lenses and looks like a pair of binoculars...The amateur astronomers observed it in June and July 2005, confirming that a planet-sized object was eclipsing the star. McCullough's team then turned to the McDonald Observatory in Texas to obtain the object's mass and verify it as a planet... hubblesite.org (http://hubblesite.org/newscenter/newsdesk/archive/releases/2006/22/full/)Yee-haw!

Van Rijn
2006-May-19, 01:01 AM
Right, amateur astronomers are starting to detect exoplanets. For instance:

http://skyandtelescope.com/printable/news/article_1546.asp

and here's some interesting information:

http://www.transitsearch.org/stardatabase/209458obs.htm

http://www.aavso.org/observing/programs/ccd/transitsearch.shtml

Kullat Nunu
2006-May-19, 05:34 AM
The more there are scopes watching the skies, the better...

Too bad transit searchs have one serious flaw: Finding a star with such a transit curve doesn't yet mean you've find an extrasolar planet; it may be a very small red dwarf or a brown dwarf, grazing binary star or something else. The star's radial velocity must be measured to make sure it really is a planet (and to measure its mass).

ToSeek
2006-May-19, 02:40 PM
Threads merged.

ngc3314
2006-May-19, 02:56 PM
The more there are scopes watching the skies, the better...

Too bad transit searchs have one serious flaw: Finding a star with such a transit curve doesn't yet mean you've find an extrasolar planet; it may be a very small red dwarf or a brown dwarf, grazing binary star or something else. The star's radial velocity must be measured to make sure it really is a planet (and to measure its mass).

I wouldn't be so harsh as calling this a serious flaw. I rather think of the transit searches as amazingly economical ways to select the handful of stars which might, with spectroscopic followup, turn out to have transiting planets. If one is after transiting planets, this is much more efficient that doing photometry of reflex-Doppler systems - there are relatively more such systems not oriented in quite the right way for us to see planets than there have been false alarms of potential photometric discoveries spoofed by a blended star or shallow partial elipse of a binary star.

This is another example of things which can be done by amateurs now that essentially no one had the capability of doing 20 years ago (let alone knew was worth doing). Detectors and computing have played equal roles, and there are amateurs whose dedication to adding to our knowledge is staggering. (Another group managed to detect the Doppler signature of the planet of Tau Boo using a 0.4-meter telescope and fiber-fed spectrograph in Arizona, for example).