- no DOT news anymore, unfortunately. The DOT is in principle
available but remains mothballed until a revival gets funded. That
requires manpower (two to four salaries) plus 50-100 kEuro/year for
running costs. You are very welcome to get yourself a very nice solar
telescope named after you!
- January 2012: Utrecht astronomy
The DOT is mothballed until somebody supplies funding for
The DOT website is now at
The DOT database is now at
with the chronological data index at
the search engine at
and the observing wiki at
- December 2011: Utrecht University
its astronomy program
(which it started back in 1642, the year Isaac Newton was
born). The DOT database server moves to Leiden Obervatory, with the
group of C.U. Keller including F.C.M. Bettonvil. The future of the
DOT is highly uncertain, but in principle the DOT remains available
for self-funded external usage.
- Spring 2011: F.C.M. Bettonvil took up a job with
G. Sliepen moved to the
- December 2010: USA/NSF-funded Helio Research concluded a
successful year of gathering many filament and prominence observations
with the DOT (over 70 Terabyte in total). Quick-look frame-select
movies are available in the DOT database. Selected image sequences are under
- July 2010: addition of a speckle
speckle reconstruction with Keller - von der Lühe restoration and
with frame selection. See DOT speckle
- Spring 2010: the start of
USA/NSF-funded Helio Research campaigns triggered much improvement of the
by G. Sliepen.
- October 2009: EC-funded DOT observer V. Olshevsky has
speckle-reconstructed the DOT observations from 2008, reducing the
large backlog that was built up after P. Sütterlin moved to the
SST. These data will appear in the DOT database.
- June 2009: the tunable narrow-band Lyot filter for Ba II 4554,
built by V. Skomorovsky and colleagues at Irkutsk, finally came on
line after extensive refurbishment and installation funded by INTAS.
Due to poor camera characteristics the images are noisy but still
suited to make Dopplergrams. You are welcome to supply a better
- Autumn 2008: DOT observers
started by EC-funded DOT observer S. Vargas Dominguez.
- February 2008: DOT database search engine
constructed by EC-funded Tim van Werkhoven.
- January 1, 2008: our major sponsors during the past years
(Utrecht University Department of Physics and
Astronomy, NWO, NOVA) have terminated their
contributions. In consequence, Dr. P. Sütterlin moved to the
Ir. F.C.M. Bettonvil transited to design studies for the
Nevertheless, DOT availability is continued partially, on a much
reduced budget. Partnerships bringing external funding for on-site
observers and telescope upgrades are welcome.
- April 2007: new DOT poster
designed by Frans Snik.
- October 2006: invitation to join in a major
DOT upgrade, with various design options.
- September 2004:
the Halpha filter
was installed in
the DOT top,
pointed at AR10675,
and produced a beautiful Halpha mosaic
of active region AR10675 with a
and a false-color morph
sequentially showing the photosphere sampled in the G band, the low
chromosphere sampled simultaneously in Ca II H, and the high
chromosphere sampled simultaneously in Halpha.
A simple version served as
Astronomy Picture of the Day
and was pictured in the
- July 2004: start of
"Open DOT" time allocation to external
- June 8, 2004:
the first Venus transit in 122 years
was recorded beautifully
- June 18, 2003: a short near-limb Ca II H
movie showing "straws”, with a companion
showing the same
scene also in the blue continuum, G band, and the wing of Ca II H.
- February 23, 2000: this
was posted as the first video on
Astronomy Picture of the Day.
- October 31, 1997: DOT First Light Ceremony featuring
Crown Prince Willem-Alexander, Science Minister Jo Ritzen and many other
dignitaries. More photographs