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Planet Discovered Using Telephoto Camera Lenses

ScuttleMonkey posted more than 8 years ago | from the shot-in-the-dark dept.

74

[rvr] writes "The Space Telescope Science Institute (STScI) reports the discovery of an extra-solar planet called XO-1b, which orbits a dim star in Corona Borealis every 4 days. To find it, the brightness of several thousand stars were regularly scanned using two mini-telescopes in Hawaii. This equipment was built using commercial hardware: two digital cameras, attached to telephoto camera lenses on a robotic equatorial mount. A team of amateur astronomers helped with their own equipment to discard or confirm dozens of suspected transits."

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Real ingenuity (4, Insightful)

bcmm (768152) | more than 8 years ago | (#15375341)

That's real ingenuity and intelligence: not throwing money at getting incredible machines to do things for you, but working out what you can do with off-the-shelf stuff and designing a system around it. People have already spent a lot on big telescopes for extrasolar planet hunting.

Re:Real ingenuity (-1, Troll)

imsabbel (611519) | more than 8 years ago | (#15375354)

Thats the dumb populistic approach.
In other words: "just because i cannot affort it, everybody has to make do with crappy tools".

Just take a minute and try to imagine what your "really ingenious" people could have done if they didnt have to waste their time and effort getting equipment doing stuff it wasnt designed for.

Re:Real ingenuity (1)

bcmm (768152) | more than 8 years ago | (#15375361)

If they had all the equipment they needed, would they have gone to the trouble of hacking up a clever system with it? I think they could have spent more and just got the same results.

Re:Real ingenuity (4, Interesting)

pimpimpim (811140) | more than 8 years ago | (#15375449)

A lot of "amateurs" actually do work that is too much of a hassle for current science. E.g. mineralogy is mainly done by amateurs these days.

I think this current news item is very good for everyone, it shows that technology (and the abbility to develop software easily and freely) actually will help to "democratize" science, making it possible for less rich groups (e.g. in developing countries, or just groups of interested amateurs) to make refreshing contributions to science! This is a good thing, as science tends to move away from the general public, getting more complicated and requiring more investments in precize equipement by the day.

my only concern is if peer reviews take place in this 'amateur' science. As all scientists, everyone wants to have a big discovery, and there is a big need to check on this if no-one tries to claim success before thorougly checking it. This urge will be no worse, no less than in "real science", but I'm just not sure if there has or will be done any checking of the results in this case. Will they publish this (I read the article half, didn't see a mention of it).

Re:Real ingenuity (4, Informative)

TapeCutter (624760) | more than 8 years ago | (#15375562)

Amature astronomers often contribute to science but are not always interested in the formalities of academia, just the fact that a technique _seems_ to work is enough for post grads to take notice and give it a try. The two groups have a long history of complementing each other.

Most "amatures" seem to use the technology to "smell the roses", making images that rival the hubble in beauty. [arcor-online.de] There is nothing really scientific about the images themselves, but then again the "blue marble" wasn't really all that scientific either.

Re:Real ingenuity (2, Informative)

graemecoates (592009) | more than 8 years ago | (#15379295)

A lot of "amateurs" actually do work that is too much of a hassle for current science. E.g. mineralogy is mainly done by amateurs these days.

In astronomy, main areas of "amateur" research work are: supernova hunting, comet hunting, variable star monitoring (probably the biggest I reckon), minor planet (asteroid) hunting and tracking including occulation timing and rotation rate determination and now work on exoplanet discovery, and even trying to find afterglows for gamma ray bursters.

In many ways, the term "amateur" almost undermines the level and quality of the work performed - in lots of cases, the data is very good indeed (and often have inspirational ways of performing the measurements) - it's just they don't get paid for it and often have a day job as well. The "pros" don't do this grunt work as it costs too much, but they will pick up the work if anything interesting is found.

Having said this, there are now dedicated survey instruments (eg WASP, NEAT to name a couple) that the pros have setup that are starting to beat amateurs to some of the observations, but often use no more advanced technology than a dedicated amateur would.

Re:Real ingenuity (1)

shawb (16347) | more than 8 years ago | (#15385422)

The difference between an amateur and a professional is going to make the two always complimentary. A professional is doing it for their career, so they therefore have to be pretty sure that what they are going to do will make money (either directly, through grants, or simply through gaining status/job security) if they want to keep putting bread on the table and making payments on their morgtage. Etymologically an amateur does what they do because they love doing it. Since it is more of a hobby to them, an amateur can do something just because they enjoy doing it. If they don't find the next big thing, no problem. They had fun doing it, and their real job paid the bills along the way. A dialog between scientific professionals and amateurs should be maintained as amateurs may be able to find something which has great promise to the scientific field but needs highly specialiced equipment to verify. On the flip side, professionals may make a discovery which would be too labor intensive to effectively complete without the aid of amateurs (SETI@home would be a decent example of this, where every cycle would have to accounted for and budgeted accordingly, while the "spare" cycles of amateurs can be used effectively for trial and error calculations and shot in the dark type hypotheses.)

On a semi-related note, the internet is becoming a more powerful tool for performing these collaborations. For instance, my father is currently trying to work on a more generalized mathematical theory of gravity (current mainstream theories basically assume spheres with consistant matter distributions, but the basic theories can fail with other objects at a close enough distance.) If he had a blog explaining his theory, other amateurs could comment and give him ideas to work on and some tricks to help test it out and refine it. It would take significant hardware, software and mathematical models which are probably out of the reach of most amateurs to actually model the gravitational interactions between, say two cubes with rotation, movement and oddly distributed masses once relativistic effects, the propogation delay in gravitonic waves/particles and other obscure phenomenon are taken into account. Actually getting something useful in engineering terms is probably out of the reach of someone running the models through a spreadsheet and eventually some visual basic on a fairly modest desktop machine.

Re:Real ingenuity (1)

Jopop (952828) | more than 8 years ago | (#15375378)

"It's not the size of the hammer, it's how you use it" ... Proven!

Re:Real ingenuity (0)

Anonymous Coward | more than 8 years ago | (#15375732)

Amateur science can be very useful to "fill the gaps" between larger funded scientific projects. However, you should not imply that "big science" does not require real ingenuity and intelligence, either: it usually requires much moreso, in fact, than amateur science. Those experiments are designed to do things that simply cannot be achieved at all on an amateur level, and are often fiendishly complex. To use this example, big extrasolar telescopes can find many planets that the story's project cannot, and to determine more about them, and can also be used for many other purposes as well.

Re:Real ingenuity (5, Informative)

Shigeru (598706) | more than 8 years ago | (#15377118)

I don't mean to diminish the cleverness of those involved in this project at all, but the article summary is a little misleading. While the discovery was made with very small-scale telescopes, the confirmation that this was actually a planet came from two large telescopes, the Harlan J. Smith Telescope (2.7 meter aperture) and the Hobby-Eberly Telescope (9.2 meter effective aperture), as the linked article mentions.

Finding extrasolar planets by the transit method, where you moniter large fields of stars and look for brightness variations as a planet passes in front of one of your targets and blocks some light, is pretty straight-forward. You tend to only need somewhere between 0.1% and 1% precision in your photometry, which requires some work to achieve, but is by no means prohibitive. So it's a good technique for amateurs to get involved with, especially when you consider that smaller telescopes tend to have larger fields of view, so you can moniter more stars at once. But the main stumbling block transit-searchers have run into is the false positive rate. The biggest surveys have found a huge false-positive rate (90-95%) among the planet candidates. It turns out there are lots of things that can make a star dim at fixed intervals, from grazing binaries to starspots.

As a result, transit planet candidates are only considered confirmed when there are measurements of a radial-velocity wobble consistent with the orbital period found by the transit. To get the radial velocity precision you need (for the Hot Jupiters transits detect, precision of tens of meters per second is sufficient), it takes a precise, high resolution spectrograph (very expensive), mounted on a large telescope (at least a couple meters).

I should also point out that transit searches are sensitive mainly to close-in planets. The sensitivity function drops very quickly as the planet moves further out (both because you need a longer sustained campaign, and because the chances of the planet's orbit crossing the star decreases). All the transit detections thus far have been from planets with several-day orbits. While this is interesting science, there's a lot of work to be done with planets in other regimes. The straight-up radial velocity technique gets you planets at seperations between 0 and 5 AU or so (over 150 planets found this way so far), the microlensing method can also detect planets at much larger orbital separations (2 or 3 planets up until now), and direct imaging is ideally suited for large-seperation planets (only the 1 good planet at this point). My point is that you can't cover this whole range of parameter space with small telescopes alone. Radial velocity and direct imaging require large investments in hardware, both in the large telescope itself and the instrumentation (disclaimer: I work on direct imaging, that's why I keep bringing it up). It's also important to note that one of the reasons people find transiting planets so interesting is the possibility of getting spectral information out of the planets. NASA's Spitzer space telescope recently detected the secondary eclipse (the loss of light when the planet is hidden behind the star) of two transiting extrasolar planets. This is pretty exciting science, since you can really compare data to models this way, but it requires some extensive telescope set-ups to get it done.

So again, this is certainly a great project for getting amateurs involved in the planet-finding game, and I"m very impressed with this result. But don't close down Keck and the VLT and Hubble just yet; there's a lot of work to be done in extrasolar planet research, and much of it requires large telescopes with new (read: expensive) instruments.

Re:Real ingenuity (4, Interesting)

doubletruncation (939847) | more than 8 years ago | (#15377142)

Actually they need to use small telescopes for this kind of project simply because large telescopes won't work. Only 1% of Sun-like stars will have a Jupiter-sized planet orbiting with a period less than ~10 days, and only 10% of these will transit from our point of view. So they need to look at ~1000 sun-like stars to have a chance of getting a single transiting hot jupiter. They're particularly interesting in finding these planets around bright stars since then you can hope to do interesting follow-up like measuring their atmospheres and reflected light. The point is, that to have any chance of finding such a planet around a bright star they need to look at very large fields of view - typically for these kind of surveys a single image will be 5 to 10 degrees on a side (which is 10 to 20 times the diameter of the full moon). It's incredibly difficult to get a very large field of view with a big telescope (for a 6 meter telescope the largest field of view camera that has been built covers half a degree by half a degree), so for this type of project small, cheap, off-the-wall telescopes are the best tools for the job. There are, in fact, a number of similar surveys using small telescopes to look for these things, and a planet (Tres-1) has already been found this way.

Planet using telephoto lens (5, Funny)

Anonymous Coward | more than 8 years ago | (#15375346)

What the hell is a planet using a telephoto lens for?
Spying on uranus?

Uranus jokes are LAME! (1)

mangu (126918) | more than 8 years ago | (#15375416)

I wish the /. lameness filter had a way to eliminate once and for all these "Uranus" jokes every time astronomy is mentioned.


That planet's name is not even pronounced ur-AY-nus, the stress is in the first sillable and the correct pronunciation is UR-ah-nus. Check any good dictionary.

Re:Uranus jokes are LAME! (0)

Anonymous Coward | more than 8 years ago | (#15375453)

Yeah, you tell him. Everyone knows that the scientists changed the name to Urectum.

Re:Uranus jokes are LAME! (3, Funny)

Frogbert (589961) | more than 8 years ago | (#15375456)

They should rename that planet to put those annoying jokes to bed once and for all. I'd like to suggest Urectum.

Re:Uranus jokes are LAME! (3, Funny)

RasputinAXP (12807) | more than 8 years ago | (#15375808)

I'm sure they'll get around to it by, oh...say..2620?

In 10 years you mean ? (1)

freaker_TuC (7632) | more than 8 years ago | (#15378396)

In 10 years net neutrality is gone, censoring is in and Uranus will be renamed to Ubehind because children could never live, grow up and the country will never be able to win the war with a terrorizing planet named Uranus.

Futurama jokes are even lamer. (1)

penguinstorm (575341) | more than 8 years ago | (#15383211)

There. Up there. In the subject. That's all I have to say.

Re:Uranus jokes are LAME! (1)

MarkRose (820682) | more than 8 years ago | (#15375469)

Might as well rename tha'un named after m'arse while yer at it.

Re:Uranus jokes are LAME! (2, Informative)

Tony Hoyle (11698) | more than 8 years ago | (#15375473)

http://dictionary.reference.com/search?q=uranus [reference.com]

You'll find both are valid, depending on your regional accent.

I personally have never heard your version.

Re:Uranus jokes are LAME! (1)

mangu (126918) | more than 8 years ago | (#15375516)

I personally have never heard your version.


Webster's New Twentieth Century Dictionary, second edition, published by Simon and Schuster, 1979, page 2010.


Isaac Asimov mentions this in his essay "The Unmentionable Planet", published in The Magazine of Fantasy and Science Fiction in November 1986. There he explains why the element uranium's name is pronounced yoo-RAY-nee-um, and Urania, the muse of astronomy is pronounced yoo-RAY-nee-uh, but the greek god's and the planet's name is pronounced YOO-rih-nus. However, he mentions, this last pronunciation isn't so good either because it's the same as "urinous".

Re:Uranus jokes are LAME! (1)

leenks (906881) | more than 8 years ago | (#15377917)

I agree with the grandparent - I have never heard this version either. I believe most people in the UK say "yer-ay-nus" (at least that is how I was taught), but because of the jokes I understand that it is now being taught as "yere-an-us".

Of course, I've forgotten that there is life outside of the UK like so many slashdotters ;-)

Re:Uranus jokes are LAME! (1)

neveragain4181 (800519) | more than 8 years ago | (#15375482)

Relax pal, where you from anyway, Uruguay?

(oh come on, I'm just kidding, let me live...)

Re:Uranus jokes are LAME! (0)

Anonymous Coward | more than 8 years ago | (#15375534)

Uruguay is oo-roo-goo-WYE

Re:Uranus jokes are LAME! (0)

Anonymous Coward | more than 8 years ago | (#15375484)

Yeah, sure it is. And that heavy metal (named after the same god) is called UR-ah-nium isn't it?

I vote that we call it... (1)

camperdave (969942) | more than 8 years ago | (#15375617)

I vote that we call it Seven of Nine.

Re:Uranus jokes are LAME! (1)

TEMMiNK (699173) | more than 8 years ago | (#15375620)

UrLameArse jokes are killing me.

Good news everyone! (1)

Koyaanisqatsi (581196) | more than 8 years ago | (#15375347)

Though I could not get to the article text, WOW! If that's what we can do now with such modest optics, I imagine it won't take much more than a decade or two before we're able to detect the signature of life in some extra-solar planet out there.

(ok, granted this planet was a gas-giant one, but big scopes are not starting to be able find more "earth-like" ones too)

As the good professor would say, "Good news everyone!"

Re:Good news everyone! (4, Informative)

cnettel (836611) | more than 8 years ago | (#15375368)

Note that we don't see the planet. We see that we see less of the light from the star. If the planet would be Earth-like (or a reasonably dense gas giant), we wouldn't get any absorption spectra clues for the chemical composition, as all wavelengths would be absorbed in the "eclipsed" region of the star's disc.

Re:Good news everyone! (1)

weird7192 (926866) | more than 8 years ago | (#15375727)

We can't see the planet, but we can smell it through my smelloscope that I built last year!

Not That Easy (3, Informative)

Rob Carr (780861) | more than 8 years ago | (#15375600)

f that's what we can do now with such modest optics, I imagine it won't take much more than a decade or two before we're able to detect the signature of life in some extra-solar planet out there.

There's an upper limit [newscientistspace.com] on what can be seen from Earth's surface. Alas, we will need space-based telescopes to find other Earths. I suppose we could find Jupiter-sized planets with lifesigns on them. Given that terrestrial life might have needed a solid surface to evolve on, I'm not sure how likely that is. Then again, it's a big galaxy, and even the weird and unlikely has to happen someplace.

Re:Not That Easy (0)

Anonymous Coward | more than 8 years ago | (#15376893)

I think the big benefit of systems like this is the reletively low cost. Build a couple hundred of these systems and make them automated or school science projects or even add them to a project like seti@home. Then use the big systems to take a look at the most promising results. It's a big galaxy and the larger telescopes can only look at a microscopic portion of it at a time.

Slylandro! (0)

Anonymous Coward | more than 8 years ago | (#15381581)

In spite of how many drahn it may take to locate them, I'm confident in the existance of our Slylandro gas bag friends. Hopefully their well intentioned 2418-B probes won't cause too many problems until then!

Let's hope this doesn't turn into Nikon vs. Canon! (3, Informative)

Glytch (4881) | more than 8 years ago | (#15375921)

Very cool project. I've heard of amateur astrophotographers using fast lenses, but this takes it to a whole new level. The lenses used in this telescope (Canon's 200mm f/1.8 L lens) not only collect an enormous amount of light, but are also among the highest quality lenses ever made.

Re:Let's hope this doesn't turn into Nikon vs. Can (0)

Anonymous Coward | more than 8 years ago | (#15379533)

There must have been some strange reason why they decided to use these Canon teles instead of conventional refractor 'scopes. I can assure you that a high quality refracting triplet APO 'scope would offer MUCH better resolution than these lenses, though these teles ARE extremely fast compared to such a 'scope. Was their detector THAT insenstive? What kind of FOV were they getting onto their detector with such a short lens?

These Canon teles really aren't all that cheap, you could buy a pretty nice pair of APO refractrors for this sort of cash.

Re:Let's hope this doesn't turn into Nikon vs. Can (1)

Glytch (4881) | more than 8 years ago | (#15380894)

From what I understand of this kind of astrophotography, fast aperture is just as important as high resolution, and there are very few off-the-shelf telephoto lenses or refractor scopes that rank high in both. As you said, a good APO refractor is extremely high-resolution and will blow almost all camera lenses out of the water, but they're slow compared to many camera lenses. On the flip side, fast camera lenses typically have awful resolution wide-open. The 200/1.8L's used here are one of those rare exceptions; these lenses are no slouches when it comes to resolution. Another good choice might have been the Nikon 200/2G, another fine, fast lens with excellent performance wide-open.

As for field of view, it depends on the size of the sensor they're using. Smaller sensors will give narrower FOV. I can't find any info in the articles as to the size of the sensors used. Here's some info [photonotes.org] on the lens. It gives vertical, diagonal and horizontal FOV in terms of film and typical DSLR sensor sizes. On 35mm film, FOV is a little over 12 degrees on the diagonal.

Correct Link (5, Informative)

timgoh0 (781057) | more than 8 years ago | (#15375356)

The second link in the article appears to be pointing to the wrong place. The correct link should be this [hawaii.edu]

Using a webcam (0)

Anonymous Coward | more than 8 years ago | (#15375370)

I discovered uranus with one once.

XO-1b (2, Funny)

waltew (764415) | more than 8 years ago | (#15375375)

By the amateur astronomers often called Bob.

"amateur astonomers" (1)

goldaryn (834427) | more than 8 years ago | (#15375387)

This equipment was built using commercial hardware: two digital cameras, attached to telephoto camera lenses on a robotic equatorial mount. A team of amateur astronomers helped with their own equipment to discard or confirm dozens of suspected transits.

I followed the link kinda hoping for a photo of a disposable camera attached to a pair of binoculars.

Bah, only a 14-inch telescope. Oh well :-)

Tight Orbit (4, Interesting)

Vlad_the_Inhaler (32958) | more than 8 years ago | (#15375391)

This Jupiter-like planet appears to be a pretty weird case. An orbit lasts 4 days, an object as large as that with an orbit as short as that must be relatively easy to discover. I suppose the thing will not be around much longer anyway - it will impact the sun there.

Re:Tight Orbit (1)

Fat Idiot (923144) | more than 8 years ago | (#15375405)

I was just going to post pretty much the same thing. TFA doesnt mention quite how "tight" the orbit is. I would love to know how a planet that large could be orbiting tight & fast. Surely the stars proximity would cause a gas giant that close to be pretty unstable.

Re:Tight Orbit (1)

i41 (804842) | more than 8 years ago | (#15375628)

How do they know this is a planet and not a large sun spot?

Re:Tight Orbit (2, Informative)

hde226868 (906048) | more than 8 years ago | (#15375709)

First of all, sunspots are more or less static in location on the surface of the star. For typical late type stars the rotation period is similar to that of our Sun, about a month, so you wouldn't see this type of variations on a timescale of 4d (we can measure the rotation speed of stars spectroscopically using standard techniques). Furthermore, even if the star rotates with a 4d period, since sunspots change in shape, each time you see the sunspot pass the surface of the star you'd see a slightly different lightcurve. Planets don't change in shape and are very symmetric objects, so the lightcurves will look very different. Finally, sunspots don't last for a very long time, so if you see a planet now and you still see it one year later, you've excluded the sunspot theory, even if you couldn't exclude it using my previous arguments.

Re:Tight Orbit (5, Informative)

hde226868 (906048) | more than 8 years ago | (#15375679)

There is no danger in the planet impacting on the star. For this you would have to invoke some mechanism that is able to get rid of the planet's orbital angular momentum, which is very difficult to acheive. So, while the planet is close to its star, it is in no danger of falling in - only very much in the future once the star leaves the main sequence and becomes a red giant. But that's some billion years in the future... (as an aside, a similar misconception is that if a star suddenly turns supernova and becomes a black hole, many people believe that planets surrounding that star would get "sucked in". For the same reason, that's not a problem either). Note that Mercury in our solar system has an 88d orbit, and has happily lived there for 4.5 billion years.

What is more worrisome is that the planet gets heated up due to its proximity to the star and is evaporated. But again, planets have an awful amount of mass, so this shouldn't be too much of a problem either. For example, there is a 4.4 jupiter masses planet around Tau Bootis, in a 3.3d orbit (http://www.exoplaneten.de/tauboo/english.html [exoplaneten.de] ), but the general estimate for objects of this kind (dubbed "hot jupiters") is that they will survive for billions of years. The reason for this is that the mass loss rate caused by the proximity of the star is still negligible compared to the mass of the planet. Take a look at the article by Ferlet et al., on p. 226 of a recent conference on explanets, the proceedings of which are at http://www.obs-hp.fr/www/pubs/Coll51Peg/proceeding s.html [obs-hp.fr] .

Re:Tight Orbit (1)

forand (530402) | more than 8 years ago | (#15376064)

Your reply assumes a two body stable orbit. This is almost certainly not the case. As soon as there is more than two bodies then we cannot make long term analytic predictions. Even if it is a two body system there are many orbits which appear to be stable for long periods then slowly decay. The orbit of the moon about the Earth is a case where the tidal forces that act between the two closely orbiting bodies allows for the bleeding off of angular momentum and the change in the orbit of the moon and the rotation of the Earth.

Re:Tight Orbit (1)

hde226868 (906048) | more than 8 years ago | (#15376306)

In most extrasolar planetary systems we have detected so far, the systems are dominated by a small number (1 to a few) of jovians. For all practical purposes these systems can be considered stable on long timescales. For our solar system, which is dominated by a few jovians in the outer solar system, while there are resonance effects between these orbits, which can significantly change the orbital parameters of the inner planets (see, e.g., Laskar, http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bi bcode=1997A%26A...317L..75L [harvard.edu] ) the system itself is quite stable (Ito and Tanikawa, http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bi bcode=2002MNRAS.336..483I [harvard.edu] ).

With the Earth-Moon system, you are citing the most extreme non-stellar case known, with two bodies close to each other which are of similar size. This system will in the end lock into a system where both bodies have a bound rotation, but the timescale of this is long (by observation more than 4.5 billion years). Note that in this case, different from what you imply, the semi-major axis of the system increases and that generally for two-body systems with a tidal exchange one tends to see a circularization of the orbit (see, e.g., Hilditch, An Introduction to Close Binary Systems, CUP, 2001). Again, such effects would stop the planet from falling into its star.

The case under discussion here more resembles the Galilean moons (several small bodies next to a large one), which is what is called in the Laplace resonance. While again there is lots of angular momentum exchange between these moons (e.g., responsible for the heating of Io), but again overall that system can be considered stable, at least according to current simulations (see, e.g., the paper by Musotto et al., accessible via http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bi bcode=2002Icar..159..500M [harvard.edu] ). Point in case: observationally we KNOW that the system has existed for 4.5 billion years.

So, to summarize, not much danger here for the planet!

Re:Tight Orbit (1)

zippthorne (748122) | more than 8 years ago | (#15376521)

The orbital radius increases because the earth's rotation velocity is greater than the moon's angular velocity. If the moon orbited the earth quickly (say.. at LEO speeds assuming that were possible...) the transfer of angular momentum would go the other way.

Also, a jovian IS significant compared to its star. especially as evidenced by the detectable wobble.

Re:Tight Orbit (1)

hde226868 (906048) | more than 8 years ago | (#15376794)

The orbital radius increases because the earth's rotation velocity is greater than the moon's angular velocity. If the moon orbited the earth quickly (say.. at LEO speeds assuming that were possible...) the transfer of angular momentum would go the other way.
yes, point taken. To finish this discussion, I have finally found the relevant paper in my files. Piet Hut showed in 1980 that one does reach a stable configuration when more than 3/4 of the total angular momentum of a system is in orbital angular momentum. In your case (moon in LEO) the angular momentum of the system would be dominated by the rotational angular momentum of the Earth and the system would indeed be unstable.
Also, a jovian IS significant compared to its star. especially as evidenced by the detectable wobble.

Again, you are right (the mass ratio of Jupiter to the galilean planets is 1:20000, while Jupiter is about 0.01 solar masses).

However, for all practical purposes you will still find that the observed system is stable, which was the original question of this thread. While hot jupiters often violate the Hut criterion and are thus formally in the unstable regime, numerical calculations show that Jovians next to main sequence stars are stable on timescales longer than the typical lifetime of a star. See, for example, Rasio et al. (1996, http://adsabs.harvard.edu/cgi-bin/bib_query?1996Ap J...470.1187R [harvard.edu] , click on arXiv preprint if you do not have a subscription to ApJ). These authors find that Jovians next to main sequence stars are stable on timescales longer than the typical age of a lower main sequence star down to orbital periods of 10 hours (their Fig. 1 is a nice summary). And this is also what is corroborated from the large number of hot Jupiters found - we just wouldn't see them if their orbits were not stable.

Re:Tight Orbit (1)

Chrispy1000000 the 2 (624021) | more than 8 years ago | (#15375720)

Actually, if there is any rocky core at all, the planet will most likely be pushed out due to tidal friction. The question is how the planet, and all the otheres, got so close there in the first place.

scuttlemonkey (-1, Offtopic)

Anonymous Coward | more than 8 years ago | (#15375406)

it's a freaking pain [theacpa.org] in the b-hind [wikipedia.org] reading scuttlemonkeys [slashdot.org] items when he insists [reference.com] on linking [htmlcodetutorial.com] every second [greenwichmeantime.com] f'ing [alexgrey.net] word. do you want people [vjoncheray.com] to be able to read [freedomtoread.ca] your blurtings [ratemypoo.com] or not? people writing like you [thebestpag...iverse.net] are a curse [fotosearch.com] on the internet [www.com] that spells REALLY BAD AND ANNOYING NAVIGATION.

that harmless rant aside, nice stuff!

its a fake (1, Funny)

Anonymous Coward | more than 8 years ago | (#15375410)

its a sony fake till they build the real planets

Telephoto? (0)

Anonymous Coward | more than 8 years ago | (#15375426)

And here I was using my macro...

Extra-Solar+Planet: 404 Not Found (1)

layer3switch (783864) | more than 8 years ago | (#15375441)

"[...] the brightness of several thousand stars were regularly scanned using two mini-telescopes [hawaii.edu] in Hawaii."

http://www.ifa.hawaii.edu/info/press-releases/extr a-solar_planet/ [hawaii.edu]

404
Not Found

umm... this is awkward...

Re:Extra-Solar+Planet: 404 Not Found (1)

peektwice (726616) | more than 8 years ago | (#15375584)

It's here Here [hawaii.edu]

From the article text (2, Insightful)

TrixX (187353) | more than 8 years ago | (#15376303)

The transit method allows astronomers to determine a planet's mass and size. Astronomers use this information to deduce the planet's characteristics, such as its density.

They infer the density from the mass and size! I knew those astronomers were really damn smart!

(I'm not laughing at the astronomers. I am laughing at the silly article writers that praise the trivial part of the astronomer work instead of the really interesting things that the astronomers do).

Re:From the article text (1)

Tango42 (662363) | more than 8 years ago | (#15376784)

Of course, they weren't even right. The transit method doesn't tell them anything about mass, they did that using the "wobble" of the star (the way most planets were discovered in the first place), as the very next paragraph explains...

Don't need a telephoto at all (4, Interesting)

gurutc (613652) | more than 8 years ago | (#15376557)

To show my folks how good their middle of the line $300 Fuji 5200 camera was I set it on the roof of my car and did a high resolution .5 second exposure of Jupiter. Then I took the cam inside, loaded the pic on the pc, and zoomed it in to show them the moons of Jupiter and some of the cloud colors on Jupiter itself.

Re:Don't need a telephoto at all (1)

Zonnald (182951) | more than 8 years ago | (#15377599)

Wow, could you share a few more details of how you achieved the shot. I have toyed with night photo's of the moon, but I am not expereinced enought to know how to set it up. I have a Olympus C740. I assume I set manual settings and all, could you give a few clues?

Re:Don't need a telephoto at all (1)

gurutc (613652) | more than 8 years ago | (#15379138)

Hi, I'd need the camera in front of me, but I'll post what I remember. Set the camera for the highest resolution possible. Turn off all the automatic settings. Turn off any 'digital' zoom features. If your camera has an 'optical' zoom set that as high as it will go. I don't know the technical terms for camera settings, but set focus to infinity and the shutter speed as slow as possible or if you can, set a timed exposure of a full second or more and use the cam's timer to snap the shot although my parents' cam wouldn't do that so I had to press the shutter button which gave me one out of 3 pictures that weren't fuzzy from my shakiness. You want to capture as much light as you can at as high a resolution as possible. You are leveraging the sensitivity and high resolution of the cam's optical sensor. You may have to experiment with this, but when you get it right you can 'magnify' your picture in any good photo editor and gain amazing 'telescopic' views of celestial objects. Hope this works for you as well as it does for me. Search the web for digital astrophotography. Most sites assume you have a telescope, but you don't need one! You can find cam-specific settings at these sites and go shoot without the scope.

The VLBA... (1)

gurutc (613652) | more than 8 years ago | (#15376572)

The array method these guys used is the principle for the Very Large Base Array on Mauna Kea. Interesting that they're still working to get the VLBA software working, and these guys in the FA are finding planets.

Quick, beat them to publication! (1)

AndroidCat (229562) | more than 8 years ago | (#15376682)

The write-up of their equipment hasn't been published in hack a day [hackaday.com] yet, so it doesn't count!

The Canon EF 200mm F2.8 L II triumphs again (4, Interesting)

heroine (1220) | more than 8 years ago | (#15376716)

Those 200mm lenses are truly underappreciated masterpieces. They are so over engineered, they can exceed telescopes for most wide field astronomy. Unlike most telescopes of equivalent quality, the EF 200mm is portable.

As time progresses and more people can afford digital SLR's, the EF 200mm F2.8 L II is going to make a lot of astonomical discoveries.

Re:The Canon EF 200mm F2.8 L II triumphs again (0)

Anonymous Coward | more than 8 years ago | (#15376810)

Sorry, but they used F/1.8 lenses, which are relative monsters compared to the 2.8 -- about double the size. These things are about the sharpest SLR lenses ever made, and are pretty heavy-duty. Mine has been through well over 100,000 actuations with no maintenance so far.

dom

Re:The Canon EF 200mm F2.8 L II triumphs again (1)

UnknownSoldier (67820) | more than 8 years ago | (#15377890)

Which lens were you referring to, with the 100,000 actuations?

Thx for the infon the lens. Been looking to upgrade...
http://www.bhphotovideo.com/bnh/controller/home?O= productlist&A=details&Q=&sku=234444&is=USA&addedTr oughType=categoryNavigation [bhphotovideo.com]

Re:The Canon EF 200mm F2.8 L II triumphs again (1)

leenks (906881) | more than 8 years ago | (#15377933)

Maybe you really did mean the 200mm f2.8 because of it's affordability, but the lens in the photos is the 200mm f/1.8 - somewhat more expensive and only available secondhand (although there are some rumours about a new version with IS)

These are most likely not telephoto lenses (2, Informative)

Flying pig (925874) | more than 8 years ago | (#15376949)

Sorry to be a lens Nazi, but these are hardly telephoto lenses. "Telephoto" does not just mean "Long focal length", it has a specific meaning. A telephoto lens has its optical centre OUTSIDE the front element; it is how it is possible to produce (say) a 600mm lens that is only 300-400mm long. These are 200mm f/1.8 and I suspect the optical centre of being inside of the front element. 200mm wide aperture lenses (which are hardly routine amateur stuff) usually work with matched telephoto adaptors at which point they DO usually become telephoto lenses in combination.

Telephotos are always an optical tradeoff where the compact dimensions are at the expense of various kinds of optical goodness. Reverse telephotos, used to give enough room in the shutter box between the film and the rear element of, say, a 21mm lens, are a different matter; they can be well designed because the greater distance to the rear element means the maximum angle of the exit rays is lower. Leitz were always able to get the best optical quality for their M series rangefinders, though, because the absence of the mirror box give fewer constraints in rear element placement.

Interestingly, if you are a lens geek, telephotos were originally developed because early news photographer cameras did not have enough extension on their baseboard bellows to focus long lenses. bellows to

Why two lenses/cameras? (1)

DieByWire (744043) | more than 8 years ago | (#15377032)

Are they using two lenses to double the light captured, or is there some other reason?

Did they use refractors vs. an off the shelf 8" or 10" SCT for higher contrast?

It would be nice to know more about the design and trade-offs of the entire camera.

Re:Why two lenses/cameras? (2, Informative)

suitti (447395) | more than 8 years ago | (#15377660)

You are looking for a slight dimming. The atmosphere of the Earth can provide slight dimming. Two cameras looking through different bits to of the Earth's atmosphere can provide extra confidence that the dimming you detect is not here at home.

Obligatory post (0)

Anonymous Coward | more than 8 years ago | (#15377473)

For all the whiners/limp wristed liberals:

Boohoo! Why do we spend money to research space when we could be paying money to the lazy welfare receipents so they can fatten up on mcdonalds. Boohoo! We could be paying for condoms for fags in some country that would rather attack us than work with us.

Burn in hell motherfuckers.

Re:Obligatory post (0)

Anonymous Coward | more than 8 years ago | (#15379418)

You are - quite literally - the wrong answer to a question that no-one asked.

FOAD

Wowzers! (1)

XO (250276) | more than 8 years ago | (#15378475)

I'm so goddamn special, they named a whole PLANET after me!

"MacGyver's Astronomy Tool Guide" (1)

Tablizer (95088) | more than 8 years ago | (#15378619)

nuf sed
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