Proc. of the GHOU 2007 in Tokyo

Stars above Arizona seen from Europe

Waldemar Ogloza*1

Time difference between Ironwood North Observatory (US, Arizona) is perfect for remote observations of dark sky from classroom before midday. Lots of teachers and pupils are using INO telescope but most of them are interested only to obtain a nice pictures of celestial object, but only few of them are using such INO fore more advanced goals

1. Introduction

The base of astronomy is observations. In the age of computers lots of pupil has an access to a web astronomical services containing thousand of nice pictures. But real observations are much more interesting and exciting for pupils. However real observations are difficult to arrange in schools. One of the reasons is problems with access to telescope and late time of observations.

One of solutions is to use the robotic telescope controlled remotely by internet. European teachers have an access to INO telescope in second half of Arizona nights it mean form 8 to 13 in Europe. Telescope is very user-friendly and easy to operate. Most of teachers use it for one filter or multicolor imaging. Same of famous targets are observed many times by different pupils. In many cases the top results from INO observations is color picture of same well known Messier object but there is much more possibilities to use this powerful tools for education.

Fig. 1. Example of nice picture for enjoys.

Fig. 2. Sombrero galaxy one of popular Messier target for INO users

Fig. 3. The Horse Head nebula color picture can be created by adding individual images.

2. More advanced observations in INO

Specific properties of INO telescope, CCD, filters and observing schedule can be taken in to account during preparation for observing. The INO telescope is much smaller than LCOGTN giants but it field of view is much wider so INO should observe different objects.

Observer can use telescope even per 5 hours (Slots A+B+C) and also download pictures obtained by others. In this way one can follow same interesting astronomical phenomena during a few hours like variable stars, occultation, asteroid’s movements etc. Using simple aperture methods and user friendly software (SalsaJ, C-Munipack) pupils can make photometric measurements of stars.

Fig. 4. M44 and M55 clusters. The two filter photometry of individual stars (with SalsaJ) can be use for H-R diagram construction.

One of goals is H-R diagram construction based of 2 filters observations of stellar cluster. Wide field of view of INO telescope is perfect for nearby open clusters or sparse globular cluster (Fig. 4.)

On ESO web page one can find interesting exercise (number 4) describing step by step how to measure age and distance of globular cluster. Such exercise will be much more interesting for pupil if they can observe globular cluster and work at their own data (www.astroex.org/english/exercises.php).

Similar example is exercise “The revolution of the moon of Jupiter” prepared by CLEA project (www3.gettysburg.edu/~marschal/clea/CLEAhome.html). It can be done using results from real observations from INO telescope. In this case except Keplerian low pupil can learn about CCD properties, filters and exposure time to obtain nice picture of such bright object.

Fig. 5. Over exposed pictures of Jupiter. The second images in Blue filter and short (0.1s) exposure time show positions of Galilean satellites

Several hours of observing time is enough to see that bright asteroid change positions among fixed stars. This simple observations can be use to learn about small bodies. Results can be analyzing using other CLEA exercise (“Astrometry of asteroids”) but based on new data.

Fig. 6. Example of asteroids observations. Different brightness is an effect or different filters used during two exposures. Telescope was pointed at asteroid using numeric coordinates prepared by teacher so pupil was very surprised that one of object is shifted during observations.

Observations of variable stars can be very important for real science. For example times of minima monitoring tell us about exotic processes in binary systems. Every mass ejection, mass exchange between components, magnetic activities of stars and other effect cause an change of orbital period duration. The monitoring of times of eclipses of such stars allows astronomers to study those exciting phenomena. In many cases there is no other way to research processes in stellar binary systems. But interpretation of observations is possible only when we have a long series of eclipses observations.

Fig. 7. Schematic view of contact binary stars and light curve. Determination of times of minima is important for scientist to study such object.

Visiting GZZ web page one can find list of stars for observations, information about data reduction and MS Excel sheet helpful for data reduction (see www.as.ap.krakow.pl/gzz)

Fig. 8. GZZ web side is useful for selection and analyze of eclipsing stars.

Fig. 9. Data analyze is easy with SalsaJ and Excel macro

Another option for INO observer is join to scientific observing campaign dedicated for long period or irregular variables. Figure 11 shows light curve collected by different observatories around the world. Same o telescopes are similar size to INO. Such observations will be very valuable for science if INO telescope will equipped with standard BVRI system filter.

Fig. 10. Eclipsing binaries observed by polish teachers with INO telescope

Fig. 11. The light curve of quasar OJ287 obtained by observers from different observatories. The INO observatory and HoU community can join to real scientific observations

3. Conclusion

The INO telescope is very powerful telescope easy to use from Europe. There are much more possibilities to use it except simple imaging. More advanced observations are necessary for better education of pupil. Even simple science makes the difference between search pictures in internet archive and remote telescope.

There are several problems during INO observations (leaking dark frames, difficulties of flat field access for observers at beginning of the night (slot A and B), focusing or deficiency of standard filters but I hope that same of them will solve in near future. Most of them are not really dangerous if observer are prepare for it.

I think that in first step of astronomical education pupil should use a simple PVC telescope or web cam detector. After this experience pupil can appreciate INO or LCOGTN telescope. Everyone should enjoy with nice color picture of famous nebulas taken by him-self but it is necessary to make one more step to make science!