Blue/Purple object in SDSS images
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While looking through SDSS images for asteroids, I happened upon this blueish-purple object. Most of the white dwarfs I've encountered have been blue in color, and most planetary nebulae I've seen have been larger than this. Is this a blue pea? Perhaps a distant planetary nebula? It has minor ultraviolet emission, and negligible X-ray emission (to what I can tell).
ID: 1237678832149528761
Image:
RA/DEC : 01 24 06.59 +08 38 06.9Posted
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by Dolorous_Edd
Hmmm UKIRT image
SDSS J012406.58+083806.9 supposed to be in the center, but it is not
ph_z = 0.187
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in WISE images there's a definite increase in brightness towards far-infrared bands (peaking at WISE 3). Most white dwarfs (as far as I know) have a decrease in brightness as one goes further into infrared. Based on this, I think the object is probably extragalactic in nature, assuming that no such object exists in the Milky Way.
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by Dolorous_Edd
Sanity check
Lets check that this is not an artifact
DSS2 Blue
Object is clearly visible in DSS Blue, not so visible in DSS Red and completly invisible in IR ( consistent with UKIRT UKIDSS image )
Object is not ALLWISE nor WISE source
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here's the location in WISE Images. It's dim enough that it's not obvious, but it's still present to band 4.
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by Dolorous_Edd in response to planetaryscience's comment.
I saw it, but it seems to absent from ALLWISE and WISE catalogs
Perhaps this could be "purple pea galaxy" ? , not a star
May wanna check 2014A&A...568A.126B for photo z ( aside from SDSS DR12 ph_z = 0.187)
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by Budgieye moderator
I think it looks like a blue star or a white dwarf. Purple or blue peas will look fuzzier, and purple peas have some red in them.
Redshift Chart http://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000ulp?page=2
image of white dwarf here.
4.5 white dwarf stars, neutron stars http://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000wrb?page=4&comment_id=53d8b9d1db90c76202001111
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by Dolorous_Edd in response to Budgieye's comment.
If it is star, why it doesn't show up in UKIDSS image? and in IR generally ( it is visible even in DSS )
+SDSS pipeline thinks it is a galaxy
BTW ( completly unrelated ) Link to
2014A&A...568A.126B is http://arxiv.org/abs/1407.2527
Update
Checked the photometric redshift from 2014A&A...568A.126B and it equals = 0.06581
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by Dolorous_Edd
Was imaged by Subaru telescope
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by Budgieye moderator
Neighbourhood check, the colour balance of other objects seems OK. There is an asteroid at one oclock of the bright star, and the asteroid appears the normal three colours.
magnify, object does seem to be quite bright and small.
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by Budgieye moderator
Maybe a cataclysmic star?Here is a cataclysmic variable star for comparison. Some are bluer, some are redder.
http://skyserver.sdss.org/dr12/en/tools/explore/Summary.aspx?id=1237652600099176775
http://www.galaxyzooforum.org/index.php?topic=277190.msg443191#msg443191 posted by elizabeth
Cataclysmic variable star thread http://www.galaxyzooforum.org/index.php?topic=277190.0
also see this binary star posted by mitch in the spectroscopic binary thread
http://www.galaxyzooforum.org/index.php?topic=10274.msg633936#msg633936
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by Dolorous_Edd
- SDSS J205914.87-061220.4 is clearly visible in Galex near UV and Far UV
SDSS J012406.58+083806.9 is only slightly visible in Galex near UV
I mean, if it was a WD / cataclysmic star , it should be a notable source of UV .. it is not
- SDSS J205914.87-061220.4 is clearly visible in DSS 2 IR
SDSS J012406.58+083806.9 is not visible in DSS 2 IR
- SDSS J012406.58+083806.9 seems to be slightly visible in WISE 3 & 4 bands and not so in band 1&2
Edit*
Listed in USNO B1 catalog as
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