The common feature of all AAVSOnet facilities is queue-scheduled observations of scientific targets, using MaxImDL for image acquisition, TheSky for telescope control, and ACP for queue scheduling. We do not support interactive telescope use, and discourage "pretty picture" observations. AAVSOnet is available free-of-charge to all dues-paying members of the AAVSO. Because of the scheduling flexibility, the optimal targets are those where an observation needs to be made once or twice per night over extended periods of time. We can do high-cadence time series of targets, but since this ties up the telescope, we usually require a good justification for such observations.

To request observations, submit the request form. After review, we will let you know if time has been awarded. After that point, observations are made and images are fully processed (dark subtract, flat field) and stored on our ftp site for your download. We also will automatically extract and perform photometry on all stars in your images; you can either access these starlists or perform your own photometry. Each project will be reviewed periodically, and those groups who are not utilizing their images may be subject to cancellation.

Sonoita Research Observatory (SRO)

SRO consists of a 35cm (C14) Schmidt-Cassegrain mounted on a Paramount near the town of Sonoita, AZ. This facility is owned and operated by John Gross, and the AAVSO has 1/3 of the time on the telescope. An SBIG STL-1001E CCD camera is used, along with Johnson/Cousins BVRI filters and a clear filter. The pixel scale is 1.25arcsec/pixel, with a 20x20arcmin field of view.

Typical seeing at SRO is 2-3 arcsec; with the pixelization, we cannot take advantage of any good seeing periods. The site gets a little dust in the Spring, but about 300 nights per year are suitable for imaging. Perhaps half of those nights are photometric, concentrating in the May-June and September-October periods.

We have found that the Paramount works well for unguided exposures up to about 300seconds. You can take exposures as short as 0.2sec, though for proper scintillation control, we recommend exposures in the 10second range or longer. The CCD has relatively low dark current and no bad pixels, though there are a couple of weak columns that flatfield out. The readnoise is 16.48 electrons; the gain is 2.03 electrons/ADU. The CCD appears to be linear to about 60K ADU.

Dirk Terrell wrote a simple Excel spreadsheet for calculating exposure times with SRO. Basically, with a one-second exposure, you will get S/N=100 at R on an 8th magnitude star. Exposures at B are 5 times longer than this, and surprisingly, exposures at Ic are two times longer. Optimal targets are from 12-15mag, but we can go as bright as 4th magnitude or as faint as 20th magnitude, depending on the need.

Some tests are underway to add a 50cm telescope to SRO. We are not sure of the photometric capabilities of this new instrument, but if it works well, the 50cm will give about twice the light-gathering power and therefore will go about a magnitude fainter.

Future Networked AAVSO Telescopes

The following telescopes will be added to AAVSONet in the coming months. Stay tuned to be notified when they are online and operational!

Mt. John University Observatory (MJUO)

The Optical Craftsman 24-inch telescope (OC60) was the first research telescope at MJUO. It has been refurbished twice in its lifetime already. The AAVSO is currently refurbishing it for a third time to convert it into a fully robotic system. The telescope is f/16 with good optics and a disk/band drive, permitting exposures of 300seconds or longer without trailing.

The CCD camera is an FLI ProLine, using a Tektronix 1024x1024 thinned, backside illuminated CCD. Pixel scale is 0.51arcsec/pixel, with a field of view of 8.8x8.8arcmin. We don\'t have specs on readnoise, gain or linearity yet. The filter wheel will contain Johnson/Cousins filters.

The AAVSO gets 2/3 time on the OC60, though New Zealand does not have optimal observing weather. About 200 nights per year will be usable, with perhaps half of that total being photometric.

Dark Ridge Observatory

Lowell Observatory donated their 24-inch Morgan Telescope to the AAVSO. This telescope (Morgan60) has been relocated to Dark Ridge Observatory in central New Mexico, where Tom Smith is refurbishing the telescope. We hope to have it online during 2009.

The Morgan60 will have a Tektronix 1024x1024 thinned, backside illuminated CCD. At f/13.5, the pixel scale will be 0.61arcsec/pixel, with a 10.4x10.4arcmin field of view. We expect to have u′BVRIC filters on the camera.

Cohen/Menke Observatory

At the AAVSO HQ, a 12-inch LX200 telescope (Cohen30) will be installed. This telescope will have an ST8XME camera and filter wheel, with a pixel scale of 0.62arcsec/pix and a field of view of 15.7x10.5arcmin. Boston is not well known as a great observing site, so we expect less than 100 nights per year to be useable, and with the bright urban light dome, this facility will not go as faint as our other sites. The advantages of the Cohen30 will be as a testbed for new instrumentation, for circumpolar objects, and to provide observations during the Southwestern July/August monsoon (when weather is best in the Boston area). This facility should be online during 2009.

Puckett Observatory

Tim Puckett (Ellijay, GA) has graciously donated the use of two wide-field refractors, large format CCD cameras, BVRI filters, and a Paramount for AAVSO use. We expect to initially use photometric nights for an all-sky survey down to 17th magnitude, and non-photometric nights for a public exoplanet survey. However, time will be available on this twin-telescope system for other bright projects. This should come online during Fall 2008.

Current Networked AAVSO Telescopes

Future Networked AAVSO Telescopes