Quote:
Originally Posted by alpal
Thanks Mike,
my calculations reveal that 6nm is OK where as a 3nm filter would
have been too narrow to pick up Ha given the recession velocity at 61 Mly away.
Redshift 0.005347
https://en.wikipedia.org/wiki/NGC_1232
As for FWHM my Maxim DL can measure it straight off
the FITS files 10 years later or whatever.
cheers
Allan |
Using 6nm filters, when deciding if I will bother capturing Ha for a galaxy, I generally use 80 million light years as a practical limit. I don't have Maxim DL.
Mike