The Type Ia supernova ( SN Ia ) 2014J in M82 ( d \approx 3.5 Mpc ) was serendipitously discovered by S. Fossey ’ s group on 2014 Jan. 21 UT and has been confirmed to be the nearest known SN Ia since at least SN 1986G .
Although SN 2014J was not discovered until \sim 7 days after first light , both the Katzman Automatic Imaging Telescope at Lick Observatory and K. Itagaki obtained several prediscovery observations of SN 2014J .
With these data , we are able to constrain the object ’ s time of first light to be Jan. 14.75 UT , only 0.82 \pm 0.21 d before our first detection .
Interestingly , we find that the light curve is well described by a varying power law , much like SN 2013dy , which makes SN 2014J the second example of a changing power law in early-time SN Ia light curves .
A low-resolution spectrum taken on Jan. 23.388 UT , \sim 8.70 d after first light , shows that SN 2014J is a heavily reddened but otherwise spectroscopically normal SN Ia .