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Need DSLR images to illustrate an eclipsing binary

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SGEO's picture
Need DSLR images to illustrate an eclipsing binary

I'm mentoring a couple high school students who want to learn about variable stars. I tried taking them out to catch an EB with binoculars. But learning how to star hop, acquire the target and make an estimate is really difficult to do in the cold of New England when we only have a couple of sessions together.

So I thought to offer them a short series of images which they could do estimates from. My CCD images are not of much use as there are not enough comps in the fov to bracket the target.

Does anyone have some DSLR images they could share that would show a variable star that has changed 1 or 2 magnitudes?

You could share them on VPhot (I'm SGEO) or, better yet, upload as an attachement to a reply to this post so they could be available to others trying to teach the youngun's about the stars!


Mark Blackford
Mark Blackford's picture
DSLR images

Hi George,

I should be able to supply suitable images covering the decline from maximum to minimum and back again. Typically I record several hundred images during an eclipse but that would be impractical for your students. Would 5 images each side of minimum be OK?

My calibrated green channel FITS images are about 6MB each, would it be ok to bin them 2x2 to reduce file size to about 1.5MB each?

I'm not sure how easy it will be to visually estimate magnitudes from the images. Better to use a photometry program to get quantitative measurements but that'll be your call. Cheers,


DSLR images of primary eclipse of Algol (Beta Persei) available

Hello George,

I have put some of my images of the Algol (Beta Persei) eclipse of 2015 Jan 13 here:

The images were taken with a 28mm lens at f/2.8 which was deliberately defocused so the star images are not overexposed. The images are raw CR2 images taken with a Canon 450D. The camera was not driven but mounted on a tripod. Please note that the time in the EXIF information is UT+1h which is the local time here.

Best regards

Wolfgang Vollmann (VOL)



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