Astronomy Field Trip to the Observatory of the University of Bologna in Loiano


Tuesday 18 March, 2003

Bologna-Map
Loiano near Bologna
On Tuesday, 18th of March, the long awaited field trip to the pinhead observatory in pinhead Loiano, near pinhead 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 pinheadPhilosophy Department at pinheadNUIG 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 pinheadLondon 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 pinheadAirport 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 pinheadUniversity Observatory is situated. We were all glad to have finally arrived after 14 hours of travelling.

Loiano scenery
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 pinhead Prof. Mike Redfern, pinhead 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
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
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

Planetsphere
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.

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

Loiano
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.
1.5m Telescope
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.
BFOSC
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.

control room
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.

0.6m telescope
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.

Sven Duscha
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.

control room
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

Bologna
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
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...


Disclaimer

This report reflects  my personal view on the field trip. I could only report on those activities I attended and all descriptions are based on how I experienced them. This report does not reflect the official version (on Dr. Ray Butler's homepage) of the NUIG Physics Department, nor that of my fellow students. If any of my fellow astronomers wants to comment on this report, feel free to email me.

Acknowledgement

I'd like to thank NUIG Physics Department, in particular, pinhead Prof. Mike Redfern who organized this field trip, and all research staff to have made this interesting astronomy experience possible. Special thanks goes to Prof. Flavio Fusi Pecci at the Astronomy Department of the University of Bologna to have granted us 10 full observation nights at their research facility.