{
  "bibcode": "2003GCN..2225....1O",
  "body": "Y. Okamoto (NIFTY-Serve Space Forum), K. Ohnishi (Nagano National\nCollege of Technology), and K. Torii (RIKEN) report:\n\n The sky area of the GRB 030329 (Vanderspek, et al., GCN 1997) was\ncontemporaneously imaged with the Yatsugatake Camera between 2003\nMarch 29 10:00 UT (97 minutes before burst) and 14:00 UT. The\nYatsugatake Camera is an ultra wide field (85 x 70 deg) video camera\n(focal length 3.5mm, f/1.4 lens equipped with Sony XC-75) placed at an\naltitude of 1000m in Yatsugatake, Japan. Images are output in NTSC\nformat after 8-s (on-chip) integrations, stored to frame memory (MSJ\nSS-10), and recorded to timelapse video tape. The camera has built-in\ninfrared-cut filter while no additional filter is used.\n\n By now, we have digitized and inspected the data between 10 minutes\nbefore and after the burst and created running mean images of four\nconsecutive frames. In these images, a neighboring V=5.1 star (41 LMi)\nis clearly detected while no transient stellar object brighter than 41\nLMi is seen at the position of the optical afterglow (Peterson and\nPrice, GCN 1985; Torii, GCN 1986). We therefore derive preliminary\nupper limit of 5.1 mag for an optical transient associated with this\nGRB on continuous 32-s time bins between 2003 March 29 11:27 UT and\n11:47 UT. Further analysis is in progress.",
  "circularId": 2225,
  "createdOn": 1052711703000,
  "email": "torii@crab.riken.go.jp",
  "subject": "GRB 030329: Optical limit (contemporaneous imaging)",
  "submitter": "Ken ichi Torii at RIKEN  <torii@crab.riken.go.jp>",
  "eventId": "GRB 030329"
}