Date: Fri, 17 Mar 2006 14:29:58 -0600 From: Richard Huziak But surely you're not suggesting that one observer looks at a mira / SR >every night? > underobserved ones). >As you say, visual curves work best with a lot of data, to >smooth out errors, but there's no reason why that curve has to be the work >of one person. > >The pitfalls of observer bias are well known! > population of observers, should there be an actual group of the vast majority of observers are 'honest' observers who do their best star you at least get a light curve by brute force. With more observers, obviously you have a better situation statistically, but observer bias is still buried within the group of all observers, so it get ignored, but in actual fact no one know if they are boring or not LD 42, 2003+57B, 0749+22C and tell me these are boring, but they had never been observed in detail before now. (It did take an intensive CCD program to scrutinize these particular stars, but detailed visual can do the same on SRs and similar stars if they are intensely observed..... have to realize that observer bias exists, and then must correct the data for it. It is done all the time. are biased. In effect, I do enough stars that I can never remember what last night's estimate was for any field, but even so, each night you On the other hand, you find that once you've done a field several dozen times, you 'learn' the field, and then estimates become easier and faster to do, and all in all your estimates simply become more accurate with practice in that field. From before......"(You can check out the 1200 days for BU Cyg, DFCyg, U Cyg, and use my observer code (HUZ))". I did this nightly Mira observing experiment as part of my Suspects I think the results turned out quite well. Another small point is that 'every night' is rarely every night. Even for the most dedicated, it is every 'clear' night, thus on the average, is 3 or 4 nights apart in good weather areas on the average, and could be weeks apart for those with poor weather locations. And even stretches of poor weather can spoil your hope to observe the cycles of long Cepheids or SR stars by introducing annoying gaps that spoil the chance of seeing a clean cycle. So I suggest to observe stars that you are most interested in every night to study them most thoroughly. Rick >Mike P. >Visit the improved website at: >www.starman.co.uk > > > >>Interesting discussion, and always the first question of new observers >>few stars that have a lot of observations so that the newbies can >>compare to the rest and gain confidence, and then also recommend a few >> >> >> > > > >>It should be remembered that visual curves work best with a lot of data >>since the curves are analysed statistically, so there is really no such >>(more) stars is difficult. >> >> * * * * * * * * * * * * * Richard Huziak Manufacturing Engineering SED Systems Saskatoon, SK, Canada