Extremely red object. Possible Brown Dwarf?


g=NaN, r=24.52, z=22.09 Not visible on SDSS. Possible brown dwarf?

Hi Kolyo_Dankov,

One of the best tools for us to distinguish BD’s from galaxies is movement, you can check out in below link if objects are moving. The tool was specially created by volunteers for the Zooniverse Backyard Worlds project lloking for Brown Dwarfs.

I don’t think i see movement for your object: http://byw.tools/wiseview#ra=218.6969&dec=-1.1187&size=50&band=2&speed=612&trimbright=98.22&linear=0.2&color=gray&mode=percent&coadd_mode=full-depth&zoom=19

From Vizier http://vizier.u-strasbg.fr/viz-bin/VizieR we get the allWISE values which aren’t too bad; Brightest in W2 and no detection in W3/W4 (both bright is bad news for BD hunters)

Your object is not visible in SDSS so not a photometric object.

Also from Vizier we get that the area is imaged by VIKING / KIDS-ESO etc (if lucky also HST), which are pretty good images in optical / IR, you can get the greyscale images and make RGB images here in following link. Weirdly enough your red source is best seen in VIKING bands but also only in VSTKIDS r band-only, whcih makes it a deep red / IR object + green only in optical? Weird.

GAMA Panchromatic Swarp Imager: http://cutout.icrar.org/psi.php

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At r=24 and z=22, you wouldn’t expect to see it in SDSS; it’s too faint. (The SDSS layer shows gri, but assuming i ~ 23, you still wouldn’t see it.)


Thank you for the reply AFJ. I am still learning to use these tools (like Vizier) and at the moment only focus on what’s visible on legacy survey site. I don’t think this red object is visible on WISE at all. I see the dot on the WISE pictures but it can be either of the 3 starts there, the other two much somewhat brighter than this object. I know brown dwarfs should be close to us and some kind of movement should be visible over the long run. Maybe if I succeed to obtain the ESO image will be able to see if the position is stable, but I can’t be sure only from WISE. I know there is a campaign for Brown Dwarfs search on WISE archive but maybe it is possible to do some discoveries with some ground based surveys as well?

I’m sure it is visible in WISE, W1 mag~17 and W2 mag~16 are pretty common values for the candidates I usually deal with.

Also I saw the detections in the WISE images from the GAMA PSI. In the WISE image viewer you are using (which one?) try to set the view window to 100 or 50 arcsec.

All the candidates I’ve submitted to the Backyard Worlds project I’ve found in the DECaLS viewer by flipping between the two WISE layers to spot movement (use spacebar to flip). And if possible check if theres something in the optical layers.

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