Planet Hunters Talk

SDSS J170008.72+291903.7

  • Dolorous_Edd by Dolorous_Edd

    Not related to PH since without LC, more like a general question

    enter image description here

    SDSS J170008.72+291903.7 is K3V star according to SDSS spectrum

    Is it normal for it to be visible in all 4 WISE bands?

    Posted

  • Shellface by Shellface

    Judging by the shape of the Vizier SED, with a visible reversal in the WISE bands, I would wager that the star hosts a disk. This is definitely not my forté, but the SED reminds me of disk hosts I've seen in literature.

    And, no, I don't expect such a faint star would be detectable as far as W3/W4 otherwise.

    The peak wavelength of the SED in ~1 micrometre (~3000 K, following Wien's law). If the K3 spectral type from SDSS is correct, then the star seems to be very reddened. This is probably logical for a disk host.

    Posted

  • Dolorous_Edd by Dolorous_Edd

    Thanks, Shellface

    However, there is a catch

    Lets have a look at Faint Images of the Radio Sky at Twenty-Centimeters

    For convinience I overlaid contours produced from FIRST on SDSS

    enter image description here

    What we are seeing is a radio galaxy with complex morphology ( Fanaroff and Riley Class II to be precise )

    It consist of the core + lobes

    Lets zoom-in on the core, it happens to be right on top of the SDSS J170008.72+291903.7

    enter image description here

    Well, problem is .. stars do not produce relativistic jets,right?

    So the only logical explanation is a background QSO or distant AGN, right? which should be exactly behind the star

    The space is big and chance alignment bound to happen, it is just first time I see such almost perfect one..

    Posted

  • Shellface by Shellface

    Wow. Again, galactic stuff is way out of my knowledge, but I think you're right. That's quite the coincidence…

    That would explain the odd peak wavelength, I suppose. I have no idea what galactic spectra look like, but I imagine the K3 spectral type isn't appropriate.

    Posted

  • Dolorous_Edd by Dolorous_Edd in response to Shellface's comment.

    I am wondering is WISE contaminated by putative bacground source?

    Star is also a GALEX source, is it normal? it is visible in Near UV

    Surprisingly, spectrum is appropriate

    Here is SDSS template for bog standard K star from DR7 Spectral cross-correlation templates

    ![enter image description here](http://classic.sdss.org/dr7/algorithms/spectemplates/spDR2-010.gif =600x400)

    Here is spectrum of our star

    enter image description here

    Just a wierd guess

    Could it be a young stellar object?

    Posted