Download Sloan Digital Sky Survey images
    http://skyserver.sdss3.org/dr9/en/tools/chart/chart.asp

    radius (degrees)
    opts: (G) Grid, (L) Label, P (PhotoObj), S (SpecObj), O (Outline), (B) Bounding Box, 
          (F) Fields, (M) Mask, (Q) Plates, (I) Invert

def getSDSSImage(ra,dec,radius=1.0,xsize=800,opt='GML',**kwargs):
    """
    Download Sloan Digital Sky Survey images
    http://skyserver.sdss3.org/dr9/en/tools/chart/chart.asp

    radius (degrees)
    opts: (G) Grid, (L) Label, P (PhotoObj), S (SpecObj), O (Outline), (B) Bounding Box, 
          (F) Fields, (M) Mask, (Q) Plates, (I) Invert
    """
    import subprocess
    import tempfile

    url="http://skyservice.pha.jhu.edu/DR10/ImgCutout/getjpeg.aspx?"
    scale = 2. * radius * 3600. / xsize
    params=dict(ra=ra,dec=dec,
                width=xsize,height=xsize,
                scale=scale,opt=opt)
    query='&'.join("%s=%s"%(k,v) for k,v in params.items())
    
    tmp = tempfile.NamedTemporaryFile(suffix='.jpeg')
    cmd='wget --progress=dot:mega -O %s "%s"'%(tmp.name,url+query)
    subprocess.call(cmd,shell=True)
    im = plt.imread(tmp.name)
    tmp.close()
    return im