Observation by Tim Haymes: Qatar-1b exoplanet transit (preliminary)

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Tim Haymes


Tim Haymes


2020 Jul 17 - 21:22


2020 Jul 21 - 11:20



  • C11 at F5.6
  • QHY174m-GPS (12/16bit CMOS)
  • TEC at -15C
  • SharpCap 3.2
  • No filter

7 sec at gain 250


Steeple Aston

Target name

Qatar 1b 21:13:32+65:09:44 (2000)


Qatar-1b exoplanet transit (preliminary)

About this image

I thought i would share this mediocre result (there is more to learn), but it is my first serious attempt at an exoplanet transit observed as part of the BAA ARPS - Exoplanets Division (Assistant Director Roger Dymock).  Im not the first to observe these in the BAA and there are much better examples. 

My data suffered from saturation in the comparison stars as the observing session progressed. Thus there are gaps where the HOPS software would not accept the photometry. Never-the-less a light curve was produced. So i am heartened.   I acquired 1370 FITS files of 7s exposure,(inc bias, dark and flat) over a period of about 3 hrs.  I spent 20min testing images for SNR and saturation before commencing. Twilight and then Moonlight interfered a bit.  The Star is magnitude 12.6 in Draco. 

Transit predictions can be seen here:   https://www.exoworldsspies.com/en/observers/

Explanation here: https://britastro.org/node/22919

PS: The GPS Camera is used for occultations.  Accurate lap-top PC time would suffice. The greatest problem encountered is not to have good guiding.  Even if the guiding is nudged, this will effect the pattern matching routines in HOPS software.
Auto-guiding is recommended, but i don't have it, so I take care to ensure the field centre doesn't shift by more that 1' - 2' arc.
The field of view was about 16 x 25 min arc. This is wide enough to get at least two comparison stars near the middle of the frame. (More comps. is better).

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