Slashdot Mirror
Open Source Photometry Code Allows Amateur Astronomers To Detect Exoplanets
An anonymous reader writes "Have access to a telescope with a CCD? Now you can make your very own exoplanet transit curves. Brett Morris, a student from the University of Maryland, has written an open source photometry application known as Oscaar. In a recent NASA Press Release, Morris writes: "The purpose of a differential photometry code – the differential part – is to compare the changes in brightness of one star to another nearby. That way you can remove changes in stellar brightness due to the Earth's atmosphere. Our program measures the brightness change of all the stars in the telescope's field of view simultaneously, so you can pull out the change in brightness that you see from the planet-hosting star due to the transit event." The program opens up exoplanet-observing to amateur astronomers and undergraduate students across the globe."
Thousands more exoplanets coming your way! Good news indeed.
Dude, seriously, everybody already realises the Slashdot so-called editors are not fully stocked up in the talent department. However you know what's even more mind-numbing than the inane stories and substandard editing on this site? That's right, it's the people incessantly whining about the aforesaid deficiencies. Give it a rest already.
The high cost was in the hardware (telescope, CCD camera) not in the software. There have been open-source or free photometry codes available for years. Admittedly not all of them trivially easy to use, but then finding and observing the expolanet itself requires some ability and understanding. A popular and quite decent photometry program which is easy to use is C-Munipack. (Which is not to say another one isn't a good thing, the more the better.)
While any open source contribution is welcome this seems somewhat narrow in scope. There are several, more general purpose applications already available at little or no marginal extra cost that could be used for this type of analysis. Many of these applications, even if not open source, allow for third party additions. If you own a photometer it'll already come with software for data reduction. If you own a telescope w/a CCD camera chances are you'll already be using a program such as MaxIm DL for camera/mount control and data reduction that can be used. Not to mention all the additional freeware (e.g. IRAF) or low cost programs available.
Exoplanet-observing was an activity. The program opens that activity to people previously not able to perform it. Watching the sky != observing exoplanets. It was actually impossible to even try to detect exoplanets with affordable hardware, now it's possible. That equates to "opening up" a specific activity which is a subset of "watching the sky".
I hope that explains it for you...
...gis sdrawkcab (usually not responding to ACs; don't bother posting as AC)
There are several difficulties that someone has to overcome in order to make observations with high enough quality to be able to detect exoplanets. First, they need a reasonably large telescope with good optics and a dark site to use it. Second, they need a reliable and well-understood detector. Fortunately CCD detectors have become fairly cheap and easy to use over the past decade, so these are well within reach of a serious amateur astronomer. Third, they need to understand what types of observations are needed to detect exoplanets. It is a little more complex than just pointing the telescope at a star and taking a few exposures. Finally, they need software that can turn their raw data into useful data, and that is not as easy as it sounds. This is where this new software comes in. Photometry software has become much smarter and much more automated since the olden days when DAOPhot ruled the roost back in the late 1980s. However, a photometry software package is only as good as the data that one puts into it. The observations must (must, must, must) be of high quality or the results will will not be. Also, the detector has to be well understood because photometry software needs to be able to correct for instrumental effects (such as slight differences in sensitivity in different parts of the detector, the amount of noise added by the detector [which also varies across the detector], and the length of time it takes to open and close the shutter, amongst other things). So, improved software is an important step forward, but it is unlikely that this new photometry package alone is going to lead to a renaissance in citizen planet hunting.
Just because you are paranoid does not mean that no-one is out to get you.
Photometry is pretty trivial. GOOD photometry is less so, and good, easy to use photometry even less so. Photometry applied to planet hunting (longitudinal differential photometry with statistical analysis), which is what I assume OSCAAR does (the web page is a little unclear just how far it goes), is another couple of levels on top. OSCAAR's contribution might well be the planet hunting bit, not the photometry bit.
Telescopes and CCDs are cheap. Learning stats and signal processing is not.
Personally, I'd rather roll my own, but then stats and signal processing is what I do.
The program opens up exoplanet-observing to amateur astronomers and undergraduate students across the globe."
Yeah, but don't those with small telescopes just run into the same problem that asteroid observers have? New systems like Pan-STARRS with gigantic field of views and resolution can scan the whole sky very quickly and then a computer can simply analyze the superior data and come up with more numerous and more accurate discoveries...drowning out the discoveries from amateurs.