Internet telescopes for variable star photometry

I use the Sierra Stars 24" in Markleeville, CA.  But it most likely does not meet your requirements.  A 30 second exposure costs about $0.80 per image.  But with a Jounson V filter I can get down to the 16th magnitude with a good SNR.  Unfiltered often gets down to the 18th magnitude for detecting CV outbursts.  The image scale is 24' square.  My V filtered images are mainly for under-observed Miras. I usually do six to eight images every other night.  The images are calibrated with darks and flats and the they show up the next morning in my VPHOT account.  You can download your images via ftp.  Check out www.sierrastars.com if you are interested.  Kevin Paxson - PKV

Hi Bob,

There are a few robotic telescopes publicly available.  You've mentioned AAVSOnet (free!) and SSO; I think Tenegra Observatories is still selling telescope time., and of course there is iTelescope  I think the Virtual Telescope (http://www.virtualtelescope.eu/) can accept requests; Telescopes In Education still operates telescopes, including one at CTIO if I remember correctly; Skynet (https://skynet.unc.edu/) handles a diverse set of telescopes; many schools have their own remote telescopes, such as the SARA consortium.  You can often form partnerships with one of these groups for observing time.  Most pay-for networks are geared towards larger telescopes and short windows of observation (so that they can support more users).  Buying time-series time on them can get very expensive.

That said, here are a couple of out-of-the box ideas.  You could form a partnership with a few other like-minded amateurs and put a robotic telescope at, say, New Mexico Skies.  You could make a substantial donation to AAVSOnet, with the requirement that you get a certain number of observing hours per year.  You could change the focus of your program to a brighter set of stars, and perhaps get extra time on our more complete Bright Star Monitor network.  You could get involved in data mining, using the long time series data from Kepler or the upcoming TESS.  You could help out with 2GSS, our initiative to cover the entire sky every night, and thereby get at least nightly cadence of your program stars.

Arne

Hi Gary,

The time allocated on each telescope for AAVSO members goes for AAVSO members.  However, that is not always 100%.  Some telescopes, like TMO61, are owned by someone else, and we get a fraction of the time on that telescope.  Some telescopes required substantial funding to refurbish, and those who paid for the refurbishment get a fraction of the time.  We try to give each site manager some time of their own on the telescope.  There are always costs involved in providing a service, and we come to the best arrangement that we can to provide the maximum use for the membership.

Arne

Hi Ed,

2GSS (2nd Generation Synoptic Survey) was described in a couple of Director's Reports.  We have a grant from the Robert Martin Ayers Sciences Fund to purchase one node of a proposed 5-node system.  Each node is an APASS-like system, using twin wide-field 30cm telescopes, taking simultaneous g' and i' images covering the sky from 10<V<16mag.  Each node can cover ~6000 square degrees per night.

The first node is partially installed at Lowell Observatory and should be fully functional this Fall.  It should generate about 30GB of data each night, containing about 10 million stars.

Arne

itelescopes

Hi Ed,

2GSS is similar to ASAS, which did an excellent job of covering southern Miras and other classes of pulsating stars.  The main differences are: two simultaneous filters (ASAS did this, too, but only published the V-band), both north and south daily coverage, 2arcsec pixels instead of 13arcsec, and two magnitudes fainter.

Where 2GSS does worse is outside of that parameter space.  Anything faint or bright is missed.  Anything near horizons, or near the moon, is missed.  Weather can cause a disruption of the nightly coverage. No time series of short-period variables is possible.  Rapid detection of transient outbursts (such as a CV non-detection for HST) is not possible, since you get at best once-per-night observations.  Any observation in a passband other than g'/i' is not possible.  I hope you get the picture!  Surveys are excellent for long-term monitoring of periodic variables (especially slowly-varying pulsators), and for discovering new variables that need to be followed-up by other ground-based facilities.  They don't help Bob's requirement of dedicated time to study a handful of stars; they do help in the selection of that handful!

Arne

As someone who has made more than 30,000 variable star observations on the Harvard plates (once or twice per month coverage, with sometimes a whole year of nothing), I would say that this once-per-clear-night coverage sounds very useful indeed.