Starship Asterisk*

Companion of a Young, Sun-like Star Confirmed

Explanation: The first direct image of an extrasolar planet orbiting a star similar to our Sun has been confirmed. Located just 500 light-years away toward the constellation Scorpius, the parent star, cataloged as 1RXS J160929.1-210524, is only slightly less massive and a little cooler than the Sun. The star is, however, much younger, a few million years old compared to the middle-aged Sun's 5 billion years. This sharp infrared image shows the young star's planetary companion positioned above and left of center. The planet is estimated to have a mass about 8 times the mass of Jupiter, and orbit a whopping 330 times the Earth-Sun distance from its parent star. The young planetary companion is still hot and relatively bright in infrared light, likely due to the heat generated during its formation by gravitational contraction. In fact, such newborn planets are easier to detect before they age and cool and become much more faint. The discovery image, shown above, was taken in 2008 but confirmed only recently by noting that the planet stayed with its parent star as background stars slightly shifted over time.

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Hi,

Why is this one called the first direct image of an exoplanet? Yesterday's APOD showed an image of a planet around Beta Pictoris taken in 2003 itself.

Thanks

Karthik wrote:Why is this one called the first direct image of an exoplanet?

It isn't. It is called the first direct image of an expolanet orbiting a star similar to our Sun.

Henning Makholm wrote:

Karthik wrote:Why is this one called the first direct image of an exoplanet?

It isn't. It is called the first direct image of an expolanet orbiting a star similar to our Sun.

I must admit that I didn't read the first line of the explanation properly. My mistake. Sorry.

The Gemini Observatory too clearly mentions this

With its initial detection by the team using the Gemini Observatory in April of 2008 this object became the first likely planet known to orbit a sun-like star that was revealed by direct imaging.

http://www.gemini.edu/node/11486

I first read about this in an article elsewhere on 29/June which gave the impression that this was the first ever exoplanet to be directly imaged. I was mulling over it when I saw today's APOD and just posted the question without reading the explanation thoroughly.

Thanks
Karthik

Exoplanet hunting really is still in it's infancy! I wonder how many earth sized planets will be found as technology gets better; and how many more will be added to the stars already observed? Kepler is working on it; and has a lot of data to sort through. I know this is a sun sized star; but it may also have smaller planets that can't be seen yet.

Hot planet, it has ceased to be a star, and cooled to emerge as PLANET.

How and when were associated with the star it orbits is the enigma, especially taking into account the distance of 330 astronomical units, the Kuiper belt is between 30 and 50 AU.

"This is the first time directly Have we seen a planetary mass object in orbit around A Likely a star like Our Sun," said David Lafrenière.

The existence of a planetary-mass companion so far from its parent star comes as a surprise, and poses a challenge to theoretical models of star and planet formation. "This discovery is yet another reminder of the truly remarkable diversity of worlds out there, and it's a strong hint that nature may have more than one mechanism for producing planetary mass companions to normal stars,” said Ray Jayawardhana

I firmly believe that the planets are the residues of some stars that have ended their lives, these are the ones that did not explode, and they are numerous.

I have said from old, and the exoplanets seem to provide evidence in that direction.

I like that says Orin Etepanek, I fully agree, we are just accessing the largest and most luminous bodies, soon further evidence of the least visible and bring us closer to understanding.
Me gusta los que señala Orin Etepanek, coincido plenamente, recien estamos accediendo a los cuerpos mas grandes y luminosos, proximamente nuevas evidencias de los menos visibles nos acercaran a la comprensión.

sorry....

I don't see any other stars in the picture - is this star located within the Milky Way Galaxy or out by itself?

biddie67 wrote:I don't see any other stars in the picture - is this star located within the Milky Way Galaxy or out by itself?

It's only 500 light-years away, so it is right here in our little corner of the Milky Way. The field of view is so narrow that there simply aren't any other stars in the image.

I had a question when this image was first selected for APOD in 2008. Do the relative sizes of the star and the planet in the image reflect the actual relative sizes of the star and planet, or the actual relative brightnesses of the star and planet, or some other artifact of the way the image was put together. When I first saw the image, and read how far the planet was from the star, I assumed that the image was captured very fortuitously when the planet was in the very small part of its orbit that put it almost behind the star from our viewpoint, assuming that its orbit is for us almost edge-on. But considering it more closely, I think I was reading too much into the image. It looks like a fiery sun orbited by a smaller planet, but is it correct to infer that the image just shows two points of light, one brighter and one dimmer? (If that is correct, the image becomes much less dramatic.)

Guest wrote:But considering it more closely, I think I was reading too much into the image. It looks like a fiery sun orbited by a smaller planet, but is it correct to infer that the image just shows two points of light, one brighter and one dimmer? (If that is correct, the image becomes much less dramatic.)

That is correct. Optically, both objects are point sources- neither is resolved. The apparent size difference is caused by diffraction and scatter effects on the different intensities.