the Tomo-e Gozen project

Kiso observatory, Institute of Astronomy, the University of Tokyo

Observations of MAXI J1820+070

Summary of observations

• Observatory: Kiso observatory, the Institute of Astronomy, the University of Tokyo
  • Location: Kiso, Nagano, Japan
  • Latitude: 35d 47m 38.7s N
  • Longitude: 137d 37m 42.2s E
  • Altitude: 1130 m
• Telescope: the 1.0-m Kiso Schmidt telescope
• Instrument: the wide-field CMOS camera Tomo-e Gozen
  • Brief summary of the Tomo-e Gozen (pdf)
• Target:
  • Name: MAXI J1820+070
  • Position: RA 18:20:21.935, Dec +07:11:07.89 (J2000)

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2018/3/14(UT)

Observer: Shigeyuki Sako, Ryou Ohsawa, Makoto Ichiki(the University of Tokyo)
Filter: No filter, sensitive in 350 to 700nm.

• 66.294 msec/frame (15 Hz)

  • Date: 2018/3/14 18h43m -- 19h20m (UT)
  • FoV: 9.9' x 7.1' (partial frame read)
  • Frames: 15 sets of consecutive 2,000 frames

    Results

    • Brightness: AB magnitude of ~12.6
    • Field image(Fig. 20180314-a), North is up.

      

    • Light curve(Fig. 20180314-b)

      top-image, middle-image, bottom-image

      　

    • Note: About 100-msec scale flare-like features with an amplitude of >100% are present in the light curve. Quasi-periodic modulations with timescale of about 100 to 200 seconds and an amplitude of about 30% are also present. The conversion factor is 0.26 ADU/e-.

• 6.149 msec/frame (160 Hz)

  • Date: 2018/3/14 19h30m -- 19h45m (UT)
  • FoV: 1.6' x 0.79' (partial frame read)
  • Frames: 15 sets of consecutive 10,000 frames

    Results

    • Field image(Fig. 20180314-c), North is up.

      

    • Light curve 1(Fig. 20180314-d1)

      

    • Light curve 2(Fig. 20180314-d2)

      

    • Light curve 3(Fig. 20180314-d3)

      　

    • Note: ~10-msec scale rapid variations are seen. The conversion factor is 0.26 ADU/e-.

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Credit

• the Tomo-e Gozen project