Look at this beauty!

https://viewer.legacysurvey.org//?ra=185.6363&dec=29.8975&layer=ls-dr9&zoom=13

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And a nearby cosmic ray [Legacy Survey Sky Browser]

That yellow blob, what is it? An #artifact, #cosmic ray? I think the shape is way too perfect to be an SN candidate. Only visible in Legacy Survey DR9 and one ‘single image exposure’ from 2016-01-13.

2016-01-13
https://c.legacysurvey.org/viewer/exposure_panels/ls-dr9-north/74000274/CCD2/?ra=185.6435&dec=29.8879&size=100

Another ‘single image cutout’
https://b.legacysurvey.org/viewer/exposure_panels/ls-dr9-south/724190/S1/?ra=185.6435&dec=29.8879&size=100

Ine :stars::dizzy:

As you can see in the single-image cutouts (Legacy Survey Sky Browser), the two g-band exposures have a large circular mask around some “bright” stars. This comes from the DECam “Community Pipeline” software that is used to calibrate the images. I need to fix our Legacy Surveys code to work around that in our next release… It only happens in some versions of the CP code – eg here it looks like the two bad images are both version decam/CP/V4.9. Anyway, when you have a ~white scene and you remove the blue (g-band) image, you get yellow :slight_smile:

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Thanks for your reply and help Dustin. :slightly_smiling_face:

Kind regards from Ine :stars::dizzy: