• The optical afterglow and host galaxy of GRB 000926 

      Fynbo, J.U.; Østensen, R.; Gorosabe, J.; Solheim, Jan Erik; Dall, T.H.; Hjorth, J.; Pedersen, H.; Andersen, M.I.; Møller, P.; Holland, S.; Smail, I.; Kobayashi, N.; Rol, E.; Vreeswijk, P.; Vrba, F.; Burud, I.; Jensen, B.L.; Henden, A.; Thomsen, B.; Canzian, B.; Castro Cer´on, J.M.; Castro-Tirado, A.J.; Cline, T.; Goto, M.; Greiner, J.; Hanski, M.T.; Hurley, K.; Pursimo, T.; Lund, N.; Tanvir, N.; Terada, H. (Journal article; Tidsskriftartikkel, 2001-04-11)
      We present the discovery of the Optical Transient (OT) of the long–duration gamma-ray burst GRB 000926. The optical transient was detected independently with the Nordic Optical Telescope and at Calar Alto 22.2 hours after the burst. At this time the magnitude of the transient was R = 19.36. The transient faded with a decay slope of about 1.7 during the first two days after which the slope increased ...
    • Three photometric methods tested on ground-based data of Q 2237+0305 

      Østensen, R.; Burud, I.; Stabell, R.; Magain, P.; Courbin, F.; Refsda, S.; Remy, M.; Teuber, J. (Journal article; Tidsskriftartikkel; Peer reviewed, 1998-09-09)
      The Einstein Cross, Q 2237+0305, has been photometrically observed in four bands on two successive nights at NOT (La Palma, Spain) in October 1995. Three independent algorithms have been used to analyse the data: an automatic image decomposition technique, a CLEAN algorithm and the new MCS deconvolution code. The photometric and astrometric results obtained with the three methods are presented. ...