Ultra-Sensitive Camera To Measure Exoplanet Sizes

Roland Piquepaille writes "US astronomers and engineers have built a new camera to precisely measure the size of planets moving around distant stars. This camera has been dubbed OPTIC — short for 'Orthogonal Parallel Transfer Imaging Camera.' According to the research team, it is 'so sensitive that it could detect the passage of a moth in front of a lit window from a distance of 1,000 miles.' I'm not sure if this analogy is right, but the team said it was able to precisely define the size of a planet called WASP-10b which is orbiting around the star WASP-10, about 300 light-years from Earth."

Comments

Re:Objects may be closer than they appear

[osu-neko]

Can it precisely define the size of Uranus?

<sigh> Poor Uranus. People who can't pronounce your name correctly are constantly making butt jokes about you, whereas those who can pronounce your name correctly are constantly making pee jokes about you...

Split infinitives are perfectly legal

[the_other_chewey]

Re those "splitinfinitive" taggers: Split infinitives are perfectly legal in English.
Yes, in American English as well.

And if they are used to change the emphasis in a phrase, they often are very useful too. They can even allow for improved clarity.
So just stop to stupidly impose latin grammar rules and conventions on another language.

By the way: Ending sentences with prepositions is generally OK as well.

Re:Split infinitives are perfectly legal

[owlnation]

Thank you!

And dear Grammar Nazis, take note that the object of language is communication. Shakespeare (perchance, fairly highly regarded for his vocabulary and poetry) made up new words and rules all the time. It's fun being creative with words.

If the grammar, spelling or sentence structure makes a passage unintelligible, then it's sometimes fine to point that out. Otherwise... shut the fuck up. Go bully people on Wikipedia like you normally do -- there you'll be very welcome.

Re:Split infinitives are perfectly legal

[lgw]

But we can be passive-aggressive like hell.

Avoid the passive voice.

doesn't sound very impressive

[kwikrick]

It measures light to a precision of one part in 2,000

So that's 11 bits of intensity information? Most professional camera CCD's are 12 bits per color. Some are 14 bits per color. Doesn't sound very impressive. And with multiple exposures, it should be possible to get a much higher resolution.

The photometric precision is three to four times higher than that of typical CCDs and two to three times higher than the best CCDs, and comparable to the most recent results from the Hubble Space Telescope for stars of the same brightness.

Hmmm, still doesn't sound too impressive. What do they mean by 'typical CCD' anyway?

In any case, it's not more sensitive than the Hubble apparently, so it's probably not going to make any breakthrough discoveries.

Nice, but not news.

Re:doesn't sound very impressive

[Anonymous Coward]

In any case, it's not more sensitive than the Hubble apparently, so it's probably not going to make any breakthrough discoveries.

Nowadays the quality of images is better from earth than from the HST. Although there is the atmosphere, on places with extremely low humidity like Mauna Kea large telescopes can be built. The HST is quite a small telescope, and with corrections of the atmosphere (like adaptive optics, lucky imaging, ...) the result is better from earth.

Other than that, I believe the scientists there when they say, they improved the precision by a factor of 2-3.

Re:doesn't sound very impressive

[hcdejong]

It measures light to a precision of one part in 2,000

So that's 11 bits of intensity information? Most professional camera CCD's are 12 bits per color. Some are 14 bits per color. Doesn't sound very impressive. And with multiple exposures, it should be possible to get a much higher resolution.

14 bits is all nice and good if your light source is the local star and you can saturate your CCD within milliseconds.
We're measuring starlight here, at maybe 10 orders of magnitude less light. Try getting 14-bit resolution at that level without drowning in noise.

WASP?

[rasputin465]

the team said it was able to precisely define the size of a planet called WASP-10b which is orbiting around the star WASP-10, about 300 light-years from Earth.

Next up for the team? Precisely measure planets around stars SPIC-20, CHINK-15, and GRINGO-117.

Equivalent of a moth at 300ly?

[Peter Cooper]

(300 light years / 1000 miles) * 2 inches == 89 588 337.2 kilometers

So (assuming an average moth is about 2 inches in size) it could make out a planet of about 90 million km (some 64 times wider than Sol) in diameter in front of a star that's 300 light years away, right?

Re:Equivalent of a moth at 300ly?

[Anonymous Coward]

Bad interpretation. They are taking about change in intensity of light.

A moth flying in front of a window.
A window is say 3'x4' = 12 sq ft = 1728 sq in.
Moth is 2" wide, 1" tall triangle = 1 sq in.

change in intensity = 1/1728 = .06%

If the star is size of sun, size of planet
  = sqrt(.06%)
  = 0.24% in diameter compared to star
  = .24/100 * 1.4e6 km = 3367 km

Re:Objects may be closer than they appear

[macraig]

I think I have a fanboi, following me around and modding my posts down. He might have started off as an Anonymous Coward making comments, but that was making him look bad so he's retreated to truly anonymous moderating. Isn't anonymity just a wonderful precious thing?

A couple corrections (from someone involved*)

[Shag]

OPTIC is not exactly a new camera, nor was it purpose-built for this. It's about four years old, and was the prototype camera for John Tonry's OTCCD (Orthogonal Transfer CCD) chips, which are now better known as the chips inside Pan-STARRS' gigapixel camera, I think. The OTCCDs have some in-chip guiding capabilities, which are kinda neat. If I recall, OPTIC spends half the year at (but not always on) the UH 2.2-meter (where I'm an operator) and half the year at WIYN.

Because OPTIC works somewhat differently than our other cameras, it doesn't exactly have a whole lot of users. John Johnson came up with the idea of using it to do light curves of transiting planets, and it turned out to work pretty well, to the point that he and his collaborators (including a couple summer REU students from the mainland) were able to get the first full-transit light curves of some particular planets.

(*involved as in, I was operating the scope that night in August and got to see those light curves in "real time." Fortunately, being thanked at the end of a scientific paper preprint earns me geek cred with my 9-year-old. ;)