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Fabrizio Pinto
Urla Iskele, Izmir, Turkey
04/28/2020
10:56 pm

Equipment Details:

The PHA asteroid 1998 OR2 as detected in Urla Iskele, Izmir Turkey. The set up was a Canon 500D with zoom lens on a tripod and no tracking. FL = 168 mm, f/5, 40 exposures of 4 sec, in 4 bursts of 10 frames. The process was repeated twice at 30 minutes intervals (here only two frames are shown). External power was applied via a Gonine ACK-ES AC Compact Power Adaptor.

Post-processing Details:

The exposures were calibrated with Bias/Dark/Flat Field frames (40 each) and stacked with DeepSkyStacker (asteroid magnitude was predicted at +10.9). The expected position of the asteroid, indispensable for proper aiming, was obtained from Stellarium. Blinking for position identification was done with Astroart (in Demo mode). Some light curving and labeling with Photoshop and Illustrator. Positive field identification with Astrometry.net. The center of the field is approximately at RA = 10h 33m, Dec = -19 deg 21 min, pixel scale = 4.71 arcsec/pixel, Up is 340 deg E of N, FOV = 95 x 55.8 arcmin.

Image Details:

The real challenge given the simplicity of the setup was aiming. Hydra is a very dim area of the sky. No star in the above two photos is visible to the unaided eye. Using a wide field lens would make the process easier but vastly increase sky background. The zoom was much better but charts were absolutely needed to aim the camera at the expected position. Shots were rehearsed with Stellarium before going under the sky. Also, the asteroid was moving very fast. At large magnification with software, the stacked up image of the asteroid (4 minutes) shows a slight elongation along the predicted direction of motion. The dimmest stars in the the above fields are mag 11.5-12.0.