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cpsTN
professor emeritus
Reged: 04/26/07
Posts: 743
Loc: Smyrna, TN USA
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Since professionals take images of the sky rather than use eyeball to eyepiece, are there any specific telescope parameters that the professionals use when searching for NEAs and other threats?
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Charles P. Sands
Zhumell 8" f/5.9 dob
Looking Up since 1982
The heavens declare the glory of God;
and the firmament sheweth His handywork
(Psalm 19:1)
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walt r
Carpal Tunnel
Reged: 02/13/07
Posts: 2421
Loc: Doylestown, PA
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For any sky surveys a wide FOV is a desirable parameter to cover as much sky as possible on each exposure.
Check out this camera for sky surveys.
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Walt
Obsession 18" f/4.45 #1370 AN/SC
MK67 Deluxe 6" f/12 Mak-Cass, Super Polaris GEM, JMI MicroMax DSC
DIY 60mm f/6 Achromat
Cookbook 245 CCD
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JAT Observatory
Space Freak
Reged: 02/20/05
Posts: 5656
Loc: Eastern PA
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Wider is better but the key is taking exposures long enough so you can see movement. The smaller the scope and the dimmer the minor planet the longer your exposure will need to be. There are 2 example on my website. Both were on the brighter side and were imaged with either a 4" refractor or a 50mm finder.
Link
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-Marcus
The problem with free speech is even the stupid have a voice.
http://jatobservatory.org
12" LX200R on a Paramount ME
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BillFerris
Carpal Tunnel
Reged: 07/17/04
Posts: 2582
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It's rare that movement is recorded in any single exposure. The typical strategy of asteroid surveys is to image each piece of the sky several times (typically 3 to 5 exposures) over the course of an hour or so. Software compares the images and looks for evidence of an object changing position against the background stars. Observations can even be compared with the positions and paths of known minor bodies. With a matter of minutes, an object can be confirmed as real, checked against the database of known objects and, if a new discovery, reported to the Minor Planet Center.
Bill in Flag
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Grand Canyon Adventure
Lowering the Threshold
18" Obsession
4.5" Meade 4500
10x50 Swift Audubon
Cosmic Voyage
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JAT Observatory
Space Freak
Reged: 02/20/05
Posts: 5656
Loc: Eastern PA
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Bill is absolutely correct, the process takes more than a single exposure. To visually detect a moving body a technique known as blink compare can be used. The process flashes or displays the images taken of an area in sequence. These images are taken hours or even day(s) apart. When played back or blinked moving bodies can be seen.
Again as Bill correctly pointed out there are software packages that will identify known minor planets within an image. Moving objects not identified in those maybe a new minor planet. I am a fan of Brian Warner's MPO Connections software as it helps automate the scope control and imaging process. It also contains the tools needed to perform Photometry, Astrometry as well as making reports to the MPC.
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-Marcus
The problem with free speech is even the stupid have a voice.
http://jatobservatory.org
12" LX200R on a Paramount ME
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nytecam
Post Laureate
Reged: 08/20/05
Posts: 4819
Loc: London UK
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UKs top astromotrist Peter Birtwhistle uses a big Meade LX200 for his MP discoveries.
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Nytecam 51N 0.1W
Meade 30cm LX200+ETX-70+DS-2090+C8+Ha+CaK PSTs SBIG SGS+homebuilt spectrographs
Starlight SXVF_M9/Lodestar/Canon 300D DSLR/Fuji E550
My observatory build-ETX-70 imaging-spectro page
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