[Aavso-photometry] IL Aqr: Campaign Update 041020

[Aaron Price]

  There is a little over a day left before the observing window opens.
I hope people take time to sleep and relax tonight in preparation for
a long 3-day marathon observing session. We received lots of good data
over the past week. We have 1500 observations in V and R from 10
observers. A light curve of the last 10 days is here:
 
http://www.aavso.org/cgi-bin/superstar2.pl?objectname=IL+AQR&lastdays=10&ccdv=on&ccdr=on

  As you can see, the individual data sets are quite good. However,
there is substantial zeropoint difference between observers. This is
going to be a challenge to combine to look for variability! As we
noted last time, *please report your airmass*. An online airmass
calculator is here:

                                          http://imagiware.com/astro/airmass.cgi

  It has the nice feature of giving you a table of airmass for an
entire evening. So you can go here once and print out a table for each
of your observing sessionts. Please report airmass in the COMMENTS:
field as "AIRMASS: X" where X is the airmass number.

  I know many of you prefer to use multiple comp stars for your
photometry. The plusses and minuses of this has been hashed out on
this discussion group many times (let's not revisit it now). But for
this object I ask that you try to *only use the 119 comp star*.  It is
the only star in the fov anywhere close to the color of IL Aqr. Just
looking at the light curve illustrates how difficult it is to combine
red star photometry from many observers. Using the 119 star makes it
far easier for us. If you insist on using multiple stars, then of
course go right ahead. Consider performing two reductions: one with
ensemble photometry and one with just the solitary 119 comp star and
see what you discover.

   On another note, if anyone has any data from 8-11 UT Oct. 18th
please submit it to the AAVSO. We have one unconfirmed report of
possible activity on the star during that period but we need
confirmation to make sure it isn't equipment induced.

== New Exoplanet Tutorials and Web Pages ==

   AAVSO Technical Assistant Kerri Malatesta wrote the current
Variable Star of the Season entry on exoplanet stars TRES-1 and
HD209458. It went online this week. For a great tutorial on exoplanet
stars, why we're doing this and more visit:
                                   
http://www.aavso.org/vstar/vsots/fall04.shtml

   In addition, our webmaster Kate Davis added a section on the
transitsearch program to the CCD Committee section: 
http://www.aavso.org/observing/programs/ccd/transitsearch.shtml

   Tomorrow I'll send a final update listing what we expect and how
I'll be reporting the results as they come in.  We still need more
observers, so if you can draft anyone into this please do so!

-- 
Aaron