Sky & Telescope - October 2019 - 27

created a setup that is essentially sealed between the telescope
objective and CCD detector, thus preventing dust from getting inside the telescope and causing image artifacts.
The scopes are mounted on a pair of Software Bisque
Paramount MX+ German equatorial mounts in one of the
roll-off-roof observatories at New Mexico Skies. They operate autonomously using the software package ACP Expert
by DC-3 Dreams. Bob Denny, DC-3 Dreams founder, was
especially helpful in creating an efﬁcient method for loading
our observing plans into ACP Expert. Since we are imaging
each ﬁeld for a minimum of 4 hours (done in blocks of three
20-minute exposures), there are more than 16,000 observing plans with almost 50,000 sky exposures loaded into the
system. And this doesn't include nightly ﬂat-ﬁeld calibration
frames and dark frames made on a regular basis.
After preliminary testing, the survey became fully operational in early 2016, and very quickly it was clear that results
were exceeding our expectations. We were capturing Hα nebulosity virtually unknown to amateur astrophotographers.
But just as enough data were accumulating to begin assembling small mosaics, there was the devastating news that
Dave had been diagnosed with an aggressive form of brain
cancer. The disease took his life the following May. You can
read more about Dave and his lasting impact on astronomy at
sites.middlebury.edu/mittelmanastrophotography.

Survey Results So Far
As of this past summer, the survey has completed at least
4 hours of exposure for more than a third of the sky (more
than 13,000 square degrees) accessible from the New Mexico
site, and we are approaching a total of nearly 25,000 square
degrees that have been imaged with at least 1 hour of exposure. The results continue to exceed expectations. As many
of the images accompanying this story show, the survey is
recording Hα nebulosity in parts of the sky traditionally
overlooked by deep-sky photographers. Most of it is too faint
to have been targets in the days of emulsion-based astrophotography, but much of it is well within reach of imagers using
modest digital equipment today.
Along the way we've spotted dozens of objects that we've
yet to identify in existing catalogs. Some, such as a faint but
clearly obvious planetary nebula in Pisces, appear to be true
discoveries, while others await further research. We've also
turned up fascinating objects that remain almost unknown
outside of a handful of professional research papers. These are
potential targets for the new generation of wide-ﬁeld astrophotographers working with modern astronomical cameras
under dark skies.
The survey has attracted the attention of professional
astronomers, some of whom are using our data in their
research. We believed this potential existed when we ﬁrst
considered doing a survey, but it's particularly rewarding to
have it become a reality.
Once the survey is completed from the New Mexico site,
we hope to follow through with our original plans of mov-

p The two modified Astro-Physics 130GTX survey telescopes (described in the accompanying text) are currently housed in one of New
Mexico Skies's roll-off roof buildings on the outskirts of Mayhill, New
Mexico, at an elevation of 7,300 feet (2,225 meters).

ing the telescopes to the Southern Hemisphere and ﬁnishing
coverage of the entire sky. The southern Milky Way is especially rich in bright Hα nebulosity, so it's exciting to imagine
what exists when we push to the limits we're reaching in the
northern sky. Long-time astrophotographer John Gleason has
been assembling deep Hα mosaics with a telescope in Australia (astrobin.com/users/dvj). And his work is fueling our
enthusiasm for continuing the southern portion of the survey.
Our project has beneﬁted from the support of many
people. In addition to Bob Denny mentioned above, they
include Roland and Marj Christen at Astro-Physics, the folks
at Software Bisque, Mike and Lynn Rice and their team at
New Mexico Skies, and especially the continuing support of
the Mittelman family.
To see more of the survey results check out the website
at mdwskysurvey.org. We continue to update the gallery
section of the site with new material as we complete more
coverage of the sky.

¢ DENNIS DI CICCO began his career at Sky & Telescope
in 1974, but his fascination with hydrogen-alpha nebulosity
stretches back to the early 1960s.
sk yandtele scope.com * OCTOBE R 2 019

http://sites.middlebury.edu/mittelmanastrophotography/ http://www.astrobin.com/users/dvj http://www.mdwskysurvey.org http://www.skyandtelescope.com

Sky & Telescope - October 2019

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