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Welcome to the Sun Hill Observatory Home Page
The Sun Hill Observatory is a part of Astronomical Institute of the Tararingapatam University
History: The Observatory was established in the year 1235 by the missionary Jiri Sosacek.
Staff: Five directors, one secretary, two research scientists, one night assistant, one ombudsman.
Instrumentation: 20 mm refracting telescope (focal length 16 cm), two sextants, one circumgenital. The 20 mm refractor has magnifying power of ten, so for example a one-Tararingapatam-crown coin observed with this telescope looks like ten-crown coin (or a one-year-old boy viewed through this telescope looks like ten-years-old boy). We had also large binocular telescope (30 mm, 6x) at our Observatory. Last year we lent it to one Soyuz crew and they have lost it during their extra vehicular activity. Thus we (unintentionaly) joined the group of a few institutions that have its own space telescope but because it is not equiped with remote control we can make no use of it.
Research interests: Variable stars, eclipsing binaries.
Current activities: Waiting for clean sky.
International collaboration: We intend to take part in the large multi-national projects named "Precise determination of geographic longitude of the North Pole", "Observation of occultations of the Moon by stars", and "Search for cold nonbaryonic dark matter in the Universe with special regard to WIMP's (weekly interacting massive particles)".
Selected papers: Cotoleti J., Kamtocumis M.: Two new W UMa-stars with amplitudes greater than 2 magnitudes. J. Astron. Sci., 89, 1992, 220.
Man of the year: This honorary title now belongs to Dr. Hned Prestanzvanit for the development of reliable method which enables to distinguish between sun spots and fly spots on photographs of solar disk.
Funny story: Flea-astronomer. As it comes, we sometimes have an uninvited guest at Sun Hill Observatory. Professor Jan Chcetoklidek visited us on one beautiful cloudy day in the autumn, 1996. After the whole afternoon spent with flying a kite he slept very well. Next morning he felt that something had irritated the skin on his back. Gibbering something about a flea-bag room he went to complain of it to our ombudsman. The ombudsman's experienced eye revealed several true flea-bites on the back of Prof. J. Chcetoklidek. One of the directors immediately called together all the people present at the Observatory. We met in the large conference hall with ten seats. Everybody looked at the back of Prof. Chcetoklidek. Then Mr. Jiri Sosacek exclaimed: "The flea-bites are arranged like stars in the constellation of Orion!" Within a moment he himself felt an itch on his arm. He tucked up his shirt-sleeve and saw a group of flea-bites representing the constellation of Great Bear. "And here is Hercules!", called Dr. M. Kamtocumis showing his hind leg. Dr. J. Cotoleti scratched his neck and asked the others: "What is this?" We unanimously replied: "It is Cassiopeia!" The secretary pointed to her exposed bosom and squeaked: "This is Pegasus!" Other and other people continued in the same manner until the director called us to work. At the end of this story we suppose the reader has understood that the uninvited guest was the flea and not Professor J. Chcetoklidek.
Everything you always wanted to know about eclipsing binaries but were afraid to ask: Can exist an eclipsing binary with the duration of eclipses greater than a half of its orbital period? Yes, it is quite possible. For example, R. K. Srivastava and B. K. Sinha (1985, Astrophysics and Space Science, Vol. 111, pp. 225-236) discovered that the eclipsing binary DX Aqr had orbital period of 11.34 hours and the average duration of its primary eclipse was 5.76 hours, in B bandpass even 6 hours.
Can the orbital period of an eclipsing binary increase and decrease simultaneously? Yes, it occurs very often. For example, R. G. Samec, B. R. Pauley, and B. J. Carrigan (1997, Astronomical Journal, Vol. 113, pp. 401-406) revealed a period change in the W UMa-type system V417 Aql and they wrote: "We calculated a period of 0.3703142 day for the first era (before JD 24 33 000) and the following improved ephemeris for the modern era: JD hel Min.I = 24 49 546.4982 + 0.3703148 x E. ... This reflects a period change of -0.16 second, which is statistically significant at the 12 sigma level."
Does XY Boo belong to the A-type of W UMa-stars as stated by C. Maceroni and F. van't Veer (1996, Astronomy and Astrophysics, Vol. 311, pp. 523-531), R. W. Hilditch, D. J. King and T. M. McFarlane (1988, Mon. Not. R. Astron. Soc., Vol. 231, pp. 341-352) and other authors? No, it does not. The radial velocity measurements done by B. J. McLean and R. W. Hilditch (1983, Mon. Not. R. Astron. Soc., Vol. 203, pp. 1-8) clearly indicate that during primary minimum of XY Boo the secondary component is occulted. Therefore the star belongs to the W-type.
News and views: During the last five years we had no clean night. This hampered our research work substantially. Therefore we are looking for an experienced observer who is able to observe variable stars even during completely cloudy nights. Another possibility is to hire a dozen of skilled cloudsweepers. However, until now no decision has been made on this issue. Potential applicants for employment should be aware of economic situation in Tararingapatam state (see Perspectives).
On April 1st (the reddest of Tararingapatam red-letter days) three government officials paid a visit to the Sun Hill Observatory. The prime minister Kaclav Vlaus, the minister of the interior Ran Juml, and the minister of scientific research Zilos Meman stopped by us during their aerial inspection of the Tararingapatam territory. Because the top of Sun Hill does not provide for aeroplane landing the government helicopter put down at the pasture near by. The Observatory personnel, two shepherds, and 120 sheeps listened to the prime minister's improvised speech about the contribution of Tararingapatam to global problems of the world.
Perspectives: This year total R&D budget of our state amounts to 200 million Tararingapatam crowns (TRC) of which 10 million is allocated to the subchapter "Astronomy". Our Observatory gained 2 million TRC (approximately 2 USD). We hope that the new government under the leadership of our democratically elected dictator will pay more attention to the needs of the Observatory.
From abroad: Since November 1st, 1997, visitors of the Petrin Hill Observatory in Prague, Czech Republic, can hear a new post-communist sound when going by Petrin Hill funicular railway. "At first I thought it should deter all passengers from travelling", says Mr. Jiri Sosacek, "but later I found out that the loud and very unpleasant sound only announced start and end of each ride."
An unnamed astronomer from Switzerland informed us that Mrs. H. Rovithis-Livaniou could take offence at finding her scientific work connected with this page. In consequence, we deleted from Sun Hill Observatory News all the paragraphs containing abstracts of papers by Mrs. H. Rovithis-Livaniou because our aim is to provide some fun and some useful reading but not to stimulate animosity among people.
FAQ: Among questions we are frequently asked is why we have our home page in Cesky hosting.
FGA: Among answers we frequently give is that servers in Tararingapatam are too expensive for us and our own fifth generation steam computer is not suitable for this purpose. The telephone line is often disrupted by wild rodents that are abundant on the slopes of Sun Hill so the only reliable connection with the rest of the world provides the secretary Broody Flatfield and her horse. On the horseback of our secretary messages arrive at the nearest village downhill, then they are shifted to the city of Tararingapatam and sent by e-mail to Dr. Petr Molik (a Czech friend of Mr. Jiri Sosacek, e-mail address: Petr.Molik@vupp.cz) who places them on this page.
Connections:Data centers: ADS, CDS, CADC, BDB, ASAS, NSVS-ROTSE, TASS, HIPPARCOS
Observatories-Europe: Athens, Baja, Bamberg, Brno-NC, Brno-univ., Bucharest, Budapest-Konkoly, Budapest-Polaris, Budapest-Uránia, Cambridge, Catania, Cracow, Hartha, Moscow-INASAN, Moscow-SAI, Mount Suhora, Pic de Chateau-Renard, Rome, Sonneberg, St Andrews, Szeged, T.Lomnica, Vienna, Warsaw-NCAC, Warsaw-univ.
Observatories-World: AAO, Ankara, Buenos Aires-IAFE, CARA, Carnegie Inst., CFHT, Cordoba, El Leoncito, Fairborn, JACARA, Korea Astron. Obs., Las Campanas, Mount John, Mount Stromlo and SSO, Toronto, Vanderbilt, Villanova
Societies: B.R.N.O., AAVSO, AFOEV, BAA-VSS, BAV, BBSAG, GEOS
Other: Astronomy meetings, Sky view, History of astronomy, Nobel Prizes 1, Nobel Prizes 2, Astrophysics preprints, IBVS, Atlas of O-C diagrams, BCB, VSOLJ Variable Star Bulletin, USNO 6th Cat. of orbits of visual binary stars, GAD, Times of minima compiled by F. Acerbi, Eclipsing binary observers, Binary Maker
Astronomers engaged in the research of eclipsing binaries (name, place, field of interest, Internet addresses; a more complete directory is available here):
|Franz Agerer||Zweikirchen, Germany||CCD photometry||WWW|
|Imre Barna Biro||Baja, Hungary||CCD photometry||WWW|
|Tamas Borkovits||Baja, Hungary||photometry||WWW|
|David Bradstreet||Saint Davids, Pennsylvania, USA||photometry, light curve analysis, author of Binary Maker||WWW|
|Roger Diethelm||Basel, Switzerland||CCD photometry||WWW|
|Gojko Djurasevic||Belgrade, Yugoslavia||photometry, light curve analysis||WWW|
|Vitaly P. Goranskij||Moscow, Russia||GCVS, photometry of novae and X-ray stars||WWW|
|Edward F. Guinan||Villanova, Pennsylvania, USA||photometry, spectroscopy, light curve analysis||WWW|
|Douglas S. Hall||Nashville, Tennessee, USA||photometry, light curve analysis||WWW|
|Petr Harmanec||Prague, Czech Republic||photometry and spectroscopy of Be-stars||WWW|
|Tibor Hegedues||Baja, Hungary||photometry, apsidal motion||WWW|
|Paul D. Hendry||Toronto, Canada||photometry, light curve analysis, Doppler imaging||WWW|
|Ladislav Hric||Tatranska Lomnica, Slovakia||photometry, light curve analysis||WWW|
|V. G. Karetnikov||Odessa, Ukraine||general properties of close binaries||WWW|
|V. S. Kozyreva||Moscow, Russia||apsidal motion||WWW|
|M. Kurpinska-Winiarska||Cracow, Poland||photometry, database of minima timings||WWW|
|Carla Maceroni||Rome, Italy||general properties of W UMa-stars||WWW|
|Pavel Mayer||Prague, Czech Republic||photometry, systems with third body||WWW|
|Stefan W. Mochnacki||Toronto, Canada||photometry, light curve analysis, magnetic activity||WWW|
|Petr Molik||Prague, Czech Republic||visual observations, properties of W UMa-stars||WWW|
|Yasuhisa Nakamura||Fukushima, Japan||photometry||WWW|
|Panagiotis G. Niarchos||Athens, Greece||photometry, light curve analysis||WWW|
|Katalin Olah||Budapest, Hungary||editor of IBVS, eclipsing binaries with spots||WWW|
|Stefan Parimucha||Kosice, Slovakia||CCD photometry||WWW|
|Theodor Pribulla||Tatranska Lomnica, Slovakia||photometry, light curve analysis||WWW|
|R. M. Robb||Victoria, British Columbia, Canada||CCD photometry||WWW|
|H. Rovithis-Livaniou||Athens, Greece||photometry, light curve analysis||WWW|
|Slavek M. Rucinski||Toronto, Canada||general properties of W UMa-stars||WWW|
|Nikolai N. Samus||Moscow, Russia||editor-in-chief of GCVS||WWW|
|Lenka Sarounova||Ondrejov, Czech Republic||CCD photometry||WWW|
|Vojtech Simon||Ondrejov, Czech Republic||Algols, cataclysmic variables||WWW|
|Laszlo Szabados||Budapest, Hungary||editor of IBVS||WWW|
|Frank Walter||Muenchen, Germany||CCD photometry, database of minima timings||WWW|
|Marek Wolf||Prague, Czech Republic||CCD photometry, apsidal motion||WWW|
|Miloslav Zejda||Brno, Czech Republic||organization of amateur observations, CCD photometry||WWW|
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This page was established (day-month-year) 29-08-1497 and last modified 14-10-2009
|Czech Corner:||Some reading for those who like it in Czech.|
|Comparison of buying power of Czech and Tararingapatam astronomers, comparison of important astronomical and economic indicators.|
|"The phenomenon of anti-flares in eclipsing binaries of the W UMa-type", a communication by Dr. P. Molik submitted to the IBVS, reply of Dr. L. Szabados, co-editor of the IBVS, reply of Dr. P. Molik.|
|P. Molik, A. Paschke: Eclipsing binary DX Aqr. Brief note intended as a poster paper for the GEOS symposium (Campo Blenio, Switzerland, 30th May - 1st June, 1998).|
|Directory:||J. Sosacek: Directory of astronomers engaged in the research of eclipsing binaries.|
|Observational data:||P. Molik: Visual observations of eclipsing binaries and cepheids in the years 1992-1996.|
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