AAVSO Alert Notice 401: Monitoring of EX Hya and DQ Her

Kunegunda Belle, Don Hoard and Steve Howell are observing
two cataclysmic variables with Spitzer during the next couple
of weeks.  They request ground-based light curves spanning
the observation intervals so that they can identify the
state each variable is in during the Spitzer visits.


1. EX HYA (12:52:24.20, -29:14:56.0, AUID 000-BBT-323)

The observations for EX Hya are scheduled for:

2009-08-18  19:25:01.1 UT 3.6micron single exposure
2009-08-18  19:26:52.9 UT 4.5micron light curve

EX Hya is an eclipsing system with 98-minute period and normally
resides about V=13.  The eclipses are only a magnitude or so in depth.


2. DQ HER (18:07:30.20, +45:51:32.0, AUID 000-BCB-341)

The observations for DQ Her are scheduled for:

2009-08-23  03:25:13.8 UT 3.6micron single exposure
2009-08-23  03:27:36.5 UT 4.5micron light curve

DQ Her normally sits at V=14.5, but remember that this is
a deeply eclipsing system (280 minute period) and during
eclipse it will dip below V=18.


The researchers request that you obtain a time series
light curve, preferably in V-band, starting at least one day
prior to and continuing one day after the Spitzer visit to the
appropriate field.  Expose long enough to get signal/noise = 30
in each individual frame.

This AAVSO Alert Notice was prepared by A. Henden


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