Newest observations

Contact information

Ursa Astronomical Association
Kopernikuksentie 1
00130 Helsinki

Ursa Astronomical Association

Variable star MAXI J1820+070 - 15.4.2018 at 03.42 - 15.4.2018 at 04.44 Helsinki, Maunula Observation number 73119

Visibility IV / V

Jorma Ryske, Etelä-Suomen kosmol. seura

I tried to highlight the MAXI J1820 + 070 light curve of the black hole in the lightening spring work, from Arto's tip. I photographed the subject in UV narrowband 387nm / 15nm, 30 exposures for 2 minutes, ie for just over an hour until the sky was too light. The hourly light curve became quite clear with a 0.20mag dimming. The absolute magnitudes are indicative because the reference stars of that particular 387nm wavelength were not known and I used the stars of region B TYC 444-2474-1 B12.25 and TYC 444-2630-1 B11.51 as some kind of calibration and BD + 07 3641 B11.10 as a reference. The second image shows a single 120s exposure with MAXI J1820 + 070 and reference stars marked.

The last two images in the visual band with the IDAS LPS-P2 filter with 5 minutes exposure, the MAXI location marked in the crop.

My SGP seems to have stamped the original FITS -3h incorrect times, the correct time for the JD time scale is + 3h / JD + 0.125.

More similar observations
Additional information
  • Observation target
    • Variable star
  • Designation
    • MAXI J1820+070
    • Näyttävä
  • Constellation
    • Ophiuchus
  • Brightness in magnitudes
    • 12.0
  • Field of view
  • 54 arc minutes
Technical information

SW 200mm / F4 Newton, QSI690, MPCC, Filter Semrock 387 / 15nm, CEM60. FoV 54'x 43 '. Bin2x2, 1.90 "/ px. Exposures 30x120s from 4/15/2018 3:42 AM EEST. North up, east left.

Send a comment

Comments are checked and moderated before publication If you want to contact the observer directly about possibilities to use these images, use the Media -form.



characters left

By sending in this comment I confirm, that I've read and understood the the observation system's privacy policy.