Proposal #559

I propose a follow-up observation of the star TrES-3 in search for an exoplanet transit signal using the BSM New Hampshire II telescope site operated by Arne Henden. This serves as a follow-up measurement for a previously measured indication of a transit signal obtained by different means. The three proposed time-windows for observation in the near future are the nights of

Fri. 4th of October 2024, 01:50 UTC until 03:40 UTC (already including 15 minutes before and after the transit)
Mon. 21st of October 2024, 01:20 UTC until 03:15 UTC (already including 15 minutes before and after the transit)
Wed. 6th of November 2024, 0:00 UTC until 01:40 UTC (already including 7 minutes before and after the transit)

The coordinates are in J2000:

RA: 17:52:06.99
Dec: +37:32:46.78

Judging from previous measurements with a half meter telescope, the ideal setting are 50 second exposure luminance (no filter) images. The apparent brightness of the star TrES-3 is 12.4 mag. The selection of the transit windows was done such that the object will be above the soft horizon of 30 degrees at any time and at least 69 degrees away from the moon. The expected change in relative flux in relation to known reference stars is expected to be around 2.7 % (27.4 ppt depth).
Reference source for the data is the platform astro.swathmore.edu ( https://astro.swarthmore.edu/transits/print_transits.cgi?single_object=0&ra=&dec=&epoch=&period=&duration=&depth=&target=&observatory_string=Specified_Lat_Long&use_utc=0&observatory_latitude=43.6875&observatory_longitude=-71.5634&timezone=CET&start_date=today&days_to_print=360&days_in_past=0&minimum_start_elevation=30&and_vs_or=or&minimum_end_elevation=30&minimum_ha=-12&maximum_ha=12&baseline_hrs=1&show_unc=1&minimum_depth=0&maximum_V_mag=&target_string=tres-3&print_html=1&twilight=-12&max_airmass=2.4&fovWidth=&fovHeight=&fovPA= ).

Should it be possible to capture not only one, but also one of the alternative transits proposed above, this could potentially increase the accuracy of the obtained results. However, a second observation does not have any priority.

The measurement is of importance as of to complete exisiting gaps in a previous measurement as well as to generate a baseline for future proposals regarding technical capabilities and choice of analysis methods.