Reply To: Beginner Move from PEP to CMOS photometry

Forums Photometry Beginner Move from PEP to CMOS photometry Reply To: Beginner Move from PEP to CMOS photometry

#618372
Dr Paul Leyland
Participant

Perhaps a start could be. What are others observing. What magnitude can useful work be carried out with say C8 or say 100mm APO.
Kevin

How long is your piece of string, in other words.

I have done photometry of exoplanet transits, variable stars (eruptives / cataclysmics mostly) and asteroids but exceedingly little on LPVs and eclipsing variables. Extragalactic luminous blue variables have also had a lot of attention but I accept that I am seriously weird in some respects.

Reasonably good estimates for magnitude ranges can be obtained from any one data point scaled by collecting area. Here is my data point, based on a 0.4m aperture. It has four times the collecting area of a C8 and so the limiting magnitude is likely very close to 1.5 magnitudes fainter. A 100mm APO has 1/16 of the collecting area and so will be around 3 magnitudes inferior to a 400mm. Note that essentially all cameras have effectively the same detector sensitivity these days and so the make of the camera is largely irrelevant from a performance point of view.

I can manage 0.1 mag precision at V=20 with a ~3 hour exposure.
I regularly do 0.05-0.03 mag measurements down to V=18 or so.
For exoplanets, ~2mmag precision can be done down to perhaps mag 12-13 unfiltered at a reasonable cadence — 1-2 minutes perhaps.

In the words of good old Usenet: HTH, YMMV, HAND.

  • This reply was modified 10 months, 4 weeks ago by Dr Paul Leyland. Reason: Add 100mm estimate
  • This reply was modified 10 months, 4 weeks ago by Dr Paul Leyland.