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Possible First Photo Of Extra-Solar Planet
dtolman writes "Space.com is reporting that the first direct image of an extra-solar planet may have been made using a new technique with the Hubble telescope. Confirmation will be made in the next few months by reimaging the star, and seeing if the planet candidate has actually changed in its orbital position."
"In response to frequent questions about plans to assign actual names to extra-solar planets, the IAU sees no need and has no plan to assign names to these objects at the present stage of our knowledge. Indeed, if planets are found to occur very frequently in the Universe, a system of individual names for planets might well rapidly be found equally impracticable as it is for stars, as planet discoveries progress."
Of course, that page was modified back in '01. Maybe there's an actual system in place now?
Russia. Planets. Name. You.
It seems to be
...
Star-name Letter
where letter goes from A to Z with decreasing mass, i.e. Upsilon Andromeda A, Upsilon Andromeda B,
If we were ants living on a Rubik's cube, differential geometry would be a little more confusing.
...it's only 4 pixels!
Not to mention that by sending it's photons, it's sending it's spectra which can tell us all sorts of things.
The blurb is slightly inaccurate... the follow-up observations aren't going to see if the object has moved around in its orbit (the distance between the primary and companion is larger than the orbit of Neptune, and the primary is a white dwarf so probably about 0.6 times the mass of the sun... from Kepler's laws, that means the period is 67% longer than Neptune's period, or about 275 years... so in 6 months it won't go very far!).
What they're going to look for is common proper motion... the white dwarf appears to move across the sky due to some combination of its motion in space and ours. If the candidate companion shows the same proper motion after 6 months, it is probably physically associated.
[TMB]
No, you're thinking about nulling interferometry, which is also very cool. :-)
What they're doing is a bit more straightforward. When you observe a point source with HST, the diffraction of the light off the supports and mirror give you a somewhat complicated not-really-symmetric pattern called the Point Spread Function (PSF). To detect a faint source right near a bright source, you need to subtract off the bright star, which means you need to know the PSF really really well so that you don't mistake some leftover light that's really from the primary as a companion.
What they're doing is observing the same field twice, once rotated slightly. The PSF doesn't depend on how the field is oriented, so faint spots that are rotated are real while ones that aren't rotated are due to instrumental effects. This means you can look at much fainter things and know if they're real or not.
To answer the original question, it will be harder the brighter the primary is... I don't know exactly what they're limits are, but it may be possible to push it to brighter stars. Working in the near-infrared, which they're doing, will help. But white dwarfs are pretty faint, so I'm not sure how much brighter a star you could get away with.
[TMB]
Actually no. Using adaptive optics with large ground based scopes (Keck, VLT) you can get some amazing images. Not that Hubble is in any way bad. It's just not the most "powerful" scope we have.
The Hubble is a 2.4m mirror. The Keck is a 10m, and the VLT is 4 8m mirrors. Adaptive Optics is really quite good at reducing atmospheric noise in images.
The Tao that can be spoken is not the one eternal Tao