As I work on a return to regular sketching, I am curious about resources for a few things-
First, is there a website that provides the current Carrington rotation #? The closest I found shows the past start/stop times for rotations and is this: http://umtof.umd.edu/pm/crn/
Obviously this implies when the current rotation started, but does not specify when it will end (yes, I could estimate). I used to have a site I could look at whenever I made a sketch that had the current information.
Second, as far as sunspot number, I know I can look at Spaceweather.com and see a sunspot number in the left hand column. I am curious, however, what site(s) others use. This question arises for me as I was trying to look at historic daily numbers to add back to some of my sketches from the past (I have many), I discovered that there are inconsistencies in the historic daily numbers - perhaps from individual observers calculating them, perhaps for being recorded at different times within a day...or who knows what else.
This leads me to another question - is there a time when the daily number is recorded/official? In other words, 0000 UTC each day, or maybe 1200, or when an observer at NOAA comes back from the first coffee break ? It would seem that it should be done at the same time each day...
Edited by Alan S, 24 October 2021 - 12:06 PM.