Astronomy Field Trip to the Observatory of the University of Bologna in Loiano
Tuesday 18 March, 2003
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| Loiano near Bologna |
On
Tuesday, 18th of March, the long awaited field trip to the
observatory in
Loiano, near
Bologna, had come. Though Bologna is not at the end of the world (but perhaps Galway is?), we had
to get up quite early in the morning to catch the coach which took us at 3:35 am from the Archway on NUIG Campus to
Dublin Airport. The transfer went smoothly despite of some fog along the way, since there was hardly any traffic on the road
around that time. A good time to get the much needed sleep to get through the rest of the day.
Prof. Markus Wörner, head of the
Philosophy
Department at
NUIG
and our lecturer for last term's course on the history of astronomy, went with our group. Despite a short delay before take off at Dublin Airport, we arrived
safely at
London Gatwick.
After the check-in for our connection flight to Bologna, we had four hours of waiting ahead of us. Some of us surrendered to the mind-boggling boredom in the seating area, whereas others used the time for a fast food snack or the joys of shopping in the
glittering boutiques at Gatwick Airport. The connection flight to Bologna took off in time and we arrived ahead of schedule at the
Airport of Bologna.
Fortunately, the Italian coach waited for us at the exit of the arrivals hall and we went on the final part of our journey through the city of Bologna and up into the
Appenine mountains to the village of Loiano where the
University Observatory is situated. We were all glad to have finally arrived after 14 hours of travelling.
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| View from the observatory mountain in Loiano |
The beautiful scenery of Loiano greeted us in the red light of the setting
sun and rooming arrangements at the
Loiano
Observatory Guesthouse were taken. But there was no time to waste. We walked
up the picturesque, yet due to the reckless driving of Italian car drivers quite
dangerous, road to the nearby restaurant to have dinner. While enjoying delicious,
though not exactly typical Italian, food
Prof. Mike Redfern,
Dr.
Ray Butler and
Prof. Markus Wörner told us about the interesting
tasks and observations that waited for us. We were randomly divided into groups
of three students to perform different activities each night at one of the telescopes.
 |
| Introduction in the 1.5m telescope dome |
Prof. Mike Redfern and
Dr. Ray Butler gave us a thorough introduction to the instruments at the observatory, the
1.5m telescope and the
0.6m telescope.
The Loiano observatory was originaly built in the 30s of the last century, at first only consisting of the small dome housing the 0.6m telescope.
Later, in the 70s the observatory was extended with the
1.5m
telescope to provide a decent state of the art instrument for observations. By today's
standards, this instrument isn't "high class" anymore, but still serves for serious research purposes. In fact, the Loiano observatory seems to be quite
frequently used by visiting astronomers and it was a great pleasure for our class to be granted 10 (including the 5 nights of the first group) nights of
observation at the University of Bologna's research facility.
 |
| 0.6m telescope in the small dome |
Each one of the lecturers served as an instructor at one of the three activities:
That night my group (Lyshia Quinn, Graeme Hayes and
me)
was to work at the
0.6m telescope.
Prof. Mike Redfern explained to us how to operate the electrical drive to open
the dome roof and the security issues related to it. Since the old dome wasn't
fully automatized (neither was the 1.5m dome, though), special attention had
to be taken to avoid collisions when rotating the dome. The dome opening had
to be kept over the telescope's aperture manually. Though the opening was big
enough not to do this with every small movement of the telescope, it had to
be checked on regular time intervals.
The telescope drive could be controlled by a (almost "ancient") PC using a small set of commands to enter
Right Ascension and Declination of a particular star to be observed. But it was also possible to
switch the drive to operate from the control room which was next to the dome itself. On the picture above showing the 0.6m telescope, the rather long focal length telescope and the large
counter weights that provide mechanical stability can be seen. The small box at the bottom houses the CCD Imaging camera with a resolution of about 1 million pixels. Compared to today's
consumer cameras this sounds like a bad resolution, but astronomers are rather interested in high
quantum efficiency than a large number of pixels. Especially for
photometry it is essential to be able to count
every single photon and to avoid any noise (e.g.
dark count). In order to achieve this as good as possible, the camera is cooled down electronically to about -20 degrees Celsius
by so-called
"Peltier Elements".
Unfortunately, due to severe problems with the telescope control we couldn't do any serious work with the 0.6m telescope that night. So we went to bed rather early, while the other two
groups performed their observations until late that night.
Wednesday 19 March, 2003
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| Planetsphere |
The next night,
19 March 2003,
Prof. Markus Wörner introduced us to the use of a planetsphere to find our way through the
constellations. Though having studied astronomy for almost
two years by now, Orion and the Big Dipper were the only constellations I could find in the sky. In contrast to my believe so far this round shaped piece of cardboard and plastic comes in
handy to find your way to the constellations in the night sky. For a "professional" astronomer it is indeed less important to know the constellations, since he is rather interested in stars
as research objects. Yet, knowing the night sky and the constellations, brings you back to the roots of this oldest science.
A computer program seems to be cooler, but it is good to still know "the old way" to do it.
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| Observing with small telescopes |
Due to the early rising of the Moon (around 8pm), the night sky soon lost
most of its beauty. Because of the bright light of the full moon (full moon
was on the day before on the 18 March 2003), we had to resort to observations
of bright objects: Jupiter and the Galilean Moons, Saturn and Saturn's rings
with the Cassini Division. With restriction to directions opposite of the moon,
we could also observe some open star clusters, e.g. the Pleiades amongst others.
We had to keep a record of all observations in our notebook along with time
and date of observation, weather and seeing conditions. Star clusters look rather
unspectacular, but in a small amateur telescope you see them at least directly
as bright "dots". When it comes to the "big" telescopes
all you get to see are grey and white dots on a computer image. Even the
biggest
telescopes can't resolve stars to a real disk, because they are simply too
far away.
Thursday 20 March, 2003
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| Village of Loiano |
The weather was really fine on most of the days. This meant not only very good conditions for observing (group 1 of our class hadn't been that lucky on the previous 5 nights), but we also used
the next day,
Thursday 20 March, to go to
Loiano. The ice cream shop at the small shopping center in Loiano is worth a visit. Apart from these culinary experiences Loiano is a nice
small Italian village, offering some beautiful buildings. Yet, I doubt that the village sees many tourists around the year. Otherwise Loiano isn't very exciting, but it offers some local amenities,
like a few Pubs, "Pizzerias" and even a cinema. The local hospital is of some advantage, since it's surely good to know, not to be too far off of essential medical care, if that had been necessary.
That night we were at the
1.5m
telescope. The
building
housing the telescope is much larger than the old one for the 0.6m telescope.
It also has a heated control room on the floor under the telescope dome, which
proves to be a bit more comfortable than the 0.6m-dome, where it could get pretty
cold, when the dome was open. The 1.5m telescope is a telescope in a "classical"
Schmidt-Cassegrain
design, which is used in most modern telescopes.
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| 1.5m Telescope |
The large primary mirror is in the black and blue "box" and can't
be seen on the photo shown. The black "nose" holds the smaller secondary
mirror that reflects the light through an opening in the primary mirror onto
the imaging instruments. Besides a state-of-the-art CCD used for imaging, the
Loiano 1.5m telescope with the BFOSC device offers a powerful device for spectroscopy.
Therefore it is more often used for
spectroscopy
purposes than mere
imaging.
The BFOSC instrument, namely the blue box at the bottom of the telescope, is
shown on the next picture.
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| BFOSC spectrometry device |
In order to avoid dark noise the CCD is cooled using liquid nitrogen.
The nitrogen has to be supplied manually from time to time by the observatory
technician,
Antonio de Blasi - as it evaporates slowly in the
thermodynamic cooling process.
The 1.5m telescope surely was most exciting in the respect that it is "a
real world and real scale" telescope which we could use. Due to the complexity
of the control software, the lack of time and probably some "concerns" about
the integrity of the instrument, we couldn't work ourselves with the instrument.
This was done by
Dr. Ray Butler and the assisting observatory technician,
Ivan Bruni, who knows the software best. But we were free to choose our
own "science targets" and the corresponding "standard stars".
Every imaging procedure must be accompanied by at least one calibration with
a "standard star" whose
magnitude
is well-measured and listed in a star almanac. A proper calibration, preferably
before and after taking "science frames", is absolutely necessary. Otherwise
one might get nice looking images, but
photometry
wouldn't be possible without reference values.
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| Dr. Ray Butler (left) and Ivan Bruni |
After a short introduction into the
fundamental properties of CCDs and
the specifications of the BFOSC spectrometer, we decided on the objects we wanted to observe. We hadn't any specific series of observations to perform, but
Dr. Ray Butler, who was our
instructor at the 1.5m telescope, assured that we covered a broad range of astronomical objects. During the night, which was throughout clear and provided excellent seeing, we observed a variety
of different objects: e.g. the
Rosette Nebula,
Open Star Clusters and
Global Star Clusters.
To make use of the BFOSC, we took a series of spectra of a
cataclysmic variable star (CV). By looking up the known periodic variation time of the star in the standard catalog,
we tried to take a series of "spectra snapshots" to cover all the phases of its cycle.
With the respectable observations we could take and not wanting to waste the good seeing conditions we stayed until morning twilight at 6:15 am. As with most astronomical observations the
outcome of our efforts won't be proven before analysis of the raw data will be done. This will be part of the third year of our
"Physics and Astronomy" course. The first processed
images can be viewed on
Dr. Ray Butler's homepage!
Update: In third year I also processed some of the data taken in Loiano and did a few
tricolour images.
Friday 21 March, 2003
This afternoon we wanted to go to Bologna and got up quite early, at 10 am - but that
is early if you stayed up all night doing observations. Unfortunately we weren't aware of the fact that the Italian
bus drivers had gone on strike that day and we waited more than one and a half hours in vain for the bus to come.
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| 0.6m telescope in the small dome |
After dinner we had concerns about the weather, since the sky was pretty cloudy. We hoped for the sky to clear up (larger gaps in the cloud cover seemed to open up already) and our instructors decided that we
should try. They were proven to be right; the sky fairly cleared up, though occassionally passing clouds or haze ruined some of the "frames" taken.
We were to work at the
0.6m telescope that night. After the first night hadn't been succesful due to the above mentioned technical problems,
Prof. Mike Redfern reminded us of the key issues to
pay attention to when moving the dome and could show us the commands on the working PC this time.
 |
| The author at the CCD control |
Working with the 0.6m telescope proved to be the most exciting part, since we could do most of the tasks on our own and had that way a real "hands-on astronomy" experience with a professional instrument.
We could decide on what objects to observe that night. This choice underlied some technical restrictions, as it is advisable to choose objects near the
Zenith to have an as thin as possible layer
of atmosphere between the star to observe and the telescope. Furthermore one would sort a series of observations to avoid unnecessary movement of the telescope. But we hadn't a definitive science program to perform,
so that we could neglect this point.
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| Working in the telescope control room |
The photo on the right, with the usual "scientists' chaotic working environment", shows
Prof. Mike Redfern with my fellow astronomy students
Lyshia Quinn and
Graeme Hayes. There we decided on what
object to choose and (as important) to find a suitable standard star in the almanac. Then the current co-ordinates of the star were calculated in an ephemeris program and typed into the telescope control software,
which guided the telescope to that position in the sky. Another Windows PC was used to control the CCD camera and to read-out the chip itself. Also the different filters were chosen on the computer and brought in
place automatically. All observations along with the filenames of the images were recorded in the notebook. Usually a read-out of the CCD device takes roughly 30 seconds, so the total
time to take frames consists of the exposure time plus the read-out time of the device and storing the resulting image file on disk. Amongst other science targets, we took frames of the
Whirlpool Galaxy.
Saturday 22 March, 2003
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| Palazzo in Bologna |
On
Saturday, 22 March, the Italian bus drivers weren't on strike
anymore and at 11am we took the one hour bus drive to Bologna. It was nice to
have the opportunity to visit
Bologna,
since this Italian city with its 400,000 inhabitants offers a nice atmosphere
and many
points
of interest. Astonishing is the large amount of historical buildings throughout
the city centre. Bologna's university was 1088 the first non-clerical school
of teaching and is in that sense the
oldest
university in Europe.
 |
| Leaning Towers |
Remarkable are the
two leaning towers of Asinelli and Garisenda.
It is possible to ascend the 498 steps of the Asinelli Tower to enjoy a magnificient view over Bologna. Suffering of vertigo I decided to stay on firm ground, while a more sportive group of my fellow astronomers took the challenge to
climb the stairs. We also visited the science museum at the
University of Bologna. Its famous
Astronomy Museum with a large collection of historical optical instruments would have been of special interest to us, but unfortunately it was
closed on Saturdays. After having taken the 5pm bus back to Loiano, we went for dinner to the restaurant. It is definitely worth to point out that the nice Italian owner of this small local restaurant supplied us with
delicious food and most of the "pasta" starters were plentiful dishes that elsewhere would have been main dishes. "Molto grazie!"
The last night we were again at the outside activity, with
Prof. Markus Wörner, to do further observations with a 125mm Meade Telescope. Using the "guided tour" of the automatic telescope drive (once it is calibrated), makes finding interesting
objects a lot easier. This night we went for several of the
Messier objects, e.g.
M44 "Beehive" open cluster. The night sky was impressive and observations of
faint deep sky objects were possible, since the Moon didn't rise before 11 pm. Besides observations with binoculars - which serve well to see
open star clusters like the
Pleiades -,
we used a standard 35mm camera, but with high sensitive film, and tried to take some astrophotography shots.
Without suitable equipment, we didn't use the camera to take photos with the telescope optics, but mounted it on a tripod to do long time exposures (60s, 120s, 180s etc.) of the sky around the
celestial North Pole.
Sunday 23 March, 2003
On
Sunday, 23 March, the day of departure had arrived. After a short night, at 9:30am we went by coach to Bologna Airport and on the 2 hours flight to London Gatwick. This time we had only to wait three hours for our connection flight to Dublin. After arrival in Dublin at 5 pm, we took the Citylink Bus back to
Galway. After 14 hours of travelling, we finally arrived in Galway at 11 pm. Having spent a joyful, interesting and succesful time in Loiano,
we all headed home to get some much needed sleep...
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