Invited Lecture, Saturday 9:30-10:00

GIA - GRUPPO ITALIANO ASTROMETRISTI, Luciano BITTESINI,  CCAF - 595 Farra Observatory (Italy)

Argument of this presentation is the Italian Astrometrists Group, an informal club of public and private amateur observatories that actively participate at the astrometric work in the world. I like to underline "informal" because there is nothing that links all of us, other than the friendship, the kind of work we do and the word "GIA".
This partnership started in 1989, when I read on a Italian astro-magazine about a Roman that was searching close to him people to do astrometry. I had a lot of time to spend in Rome during my stand-by service, so I called Silvano CASULLI in Colleverde and we soon became family friends.
CASULLI at that time was in touch with Tonino VAGNOZZI of Stroncone observatory and with Ermes COLOMBINI of S.Vittore; in Italy they were doing photographic astrometry like Johann BAUR at Chions, Ulisse QUADRI in Bassano Bresciano and Luciano LAI in Cavriana.
This group became naturally the spring from where we started to take experiences, software and operating instructions (think that the computers we had where the firsts Texas, HP, Commodore or Apple II).
Many of us built the blink-comparators to identify the moving objects and some measuring machines to derive the positions between the stars, others started writing software.
In 1991 started the revolution when we bought the first three ST4's to have a better guide while taking pictures of faint moving objects. After less than a year we ordered the first two ST6's and then we started our asteroid fight sending in March 1993 our first discovery positions.
The first observatory we talk about is Colleverde di Guidonia, just outside the big Rome highway ring; Silvano CASULLI works there from a balcony at 5th floor with another balcony above him, thus he can see only less than half east sky with a lot of light pollution southwards. Nevertheless he continues to follow and discovery minor bodies reaching magnitudes well above 19. _ 0.4m f/3.2 Newton ST4 ST6;
Just few kilometers apart lies Mentana with Stefano VALENTINI: since 1994 he joined GIA group writing a lot of software for astrometry: he started with the one for Windows 3.1 and then made an integration of many packets for Windows 95; now he has more complex version able to do even precoveries on old plates; all this software is available to every one asks it him.
Next observatory is Stroncone, just above the south hills of Terni, about 100 km north of Rome. Tonino VAGNOZZI and many other friends had built here a fully automatic telescope capable of high performance due to site elevation, about 800 meters and due to the absence of light pollution southward.
This site has been home of a continuos upgrading of software files that allowed all GIA, since 1992, to read catalogs, blink pictures and compute positions in a very sophisticated manner. _ 0.50m f/3.2 Ritchey-Chretien ST4 ST6;
Few kilometers to the east Polino that just started astrometric work. _ 0.40m f/5 Newton ST4 ST6
Going northbound, on the Appennini chain north-west of Florence and north-east of Pisa you may find one of the two observatories of GIA open to the public, S. Marcello. These observatories make a strong activity with students, school groups and common people on a regular basis monthly and even by appointment with teachers: they host even "open nights" during selected astronomical events. Here has been discovered the first Amor in Italy, 1994 QC. _ 0.40m f/5 Newton-Cassegrain ST4 ST5 new telescope and dome
More close to Florence works one of the few ladies of the GIA, Maura TOMBELLI, who with his instrument actually follows NEOs and comets, but time ago worked with S. Marcello and even with Asiago observatory, a professional structure of Padua University, where she contributed to discover about 80 objects. _ 0.30m f/5.7 Schmidt-Cassegrain ST6

Another 100 km northbound, half of the climb of the hill that overstays Bologna, operates the older staff of the italian astrometrists: founded by Ciro VACCHI, that left all of us two years ago, more than 80, with a severe deformity at his legs due to a poliomyelitis while young, and Giorgio SASSI, he more than 80 too and still active, took CCD pictures that Ermes COLOMBINI, in Modena, interested in numerical computations of orbits, identifies and collects data from . _ 0.45m f/5 Newton 0.32m f/2.5 Schmidt ST6

I like to remember that VACCHI and SASSI passed through all the steps of making a telescope, updating it, applying electronics, taking film pictures, processing them, applying a CCD, taking CCD pictures with a computer and interfacing and operating a telescope by computer: all handmade by them. If you go to visit them you may recap all the history of astrometry.
North of Milan, between the two branches of Como lake (humanists here may remember Alexander MANZONI, a famous Italian writer with his "Promessi Sposi" "Betrothed") at about 1500 m of elevation stays a dome where the team of Sormano most of the time follows NEOs.
Even here there is people that develops software to follow fast moving objects, to make a preliminary identification, to compute ephemeris and orbits. _ 0.50m f/4.2 Ritchey-Chretien ST4 ST6
In their web site they have a page dedicated to the objects that need more observations and when the observation arc is big enough they compute the real values of approach to the Earth (MOID), from the past century to the next two, in order to make easier the precoveries on old plates.
In the next years they are planning a new 600 mm telescope and a 2048x2048 CCD.
If we go to the east just south of Verona we meet the observatory of Luciano LAI, another of the "film astrometrists".
He started in Cavriana observatory (571), about 20 km to the west of his actual site, with the discovery of Verona and with a Jupiter observation program born after a request of the French Dragesco, to continue an older program of Lowell Observatory. The program ended after 4 years with the advent of planetary probes when all instruments where ready and well calibrated to operate: LAI said that probably Dragesco may had some other problems causing his withdrawal from the project.
After this research he moved to his home in Dossobuono where he continues experimenting with optics, electronics and CCDs while doing astrometry. _ 0.40m Newton f/5 ST4 ST6
Passing Venice eastwards, after 100 km we reach Remanzacco (Udine) where Giovanni Sostero to the comet astrometry prefers to do, with remarkable results, photometry with standard BVRI  and interference filters.
Few kilometers east is Farra where stays the last Italian observatory: we are open to the public like S. Marcello and our annual rate of visitors is above 2000, included more than 50 classes of schools (we have students visiting us from elementary to high-school). There are two main telescopes: the one you see in the slide below a dome is the former one of Mr. Baur and makes all the astrometric work while the other, under a box with a sliding roof, it's a new 300, completely automatic, that will be used for visual observation during visiting times and for automatic research at the end of the guest sessions. _ 0.40m f/4.5 Newton-Cassegrain 0.30m f/4 Newton ST4 ST6
The last of us is not Italian, it stays here: Korado KORLEVIC worked hard to teach polytechnic in a middle-school, organizing every year many stages of astronomy for his students and for all others that come from the whole Croatia; after the war they remained the only working observatory in this country. Now he left his job in the public education and acts as mentor for high IQ students classes held at the observatory. They participate to our meetings and activities and contribute with software, telescope interfacing and observing time. I like to remenber that in the scoreboard of this observatory there are three comets_ 0.41m f/4.3 Newton-Ross ST6 2048x2048

 Lecture, Saturday 10:00-10:15

DETECTING AND MEASURING FAINT POINT SOURCES WITH A CCD, Herbert Raab, Davidschlag Observatory, Astronomical Society of Linz, Austria, e-mail: herbert.raab@utanet.at

Stars, Asteroids, and even the nuclei of comets are point-sources of light. In recent times, most observers use CCDs to observe these objects, so it might be worthwhile to think about some details of detecting and measuring point sources with a CCD.

First, we discuss the properties of point-sources, and how we can describe them with a small set of numerical values. Then, we identify the sources of noise in our imaging systems, and we see how both signal and noise increase with integration time. By estimating the signal to noise ratio (SNR) of a faint point source for some examples, we investigate how various parameters (like integration time, telescope aperture, or pixel size) affect the SNR of point sources. As a result, we try to optimize the pixel scale so that we gain the best possible SNR while retaining all information of the sources. Finally, we estimate the photometric and astrometric error of point sources at various signal to noise ratios.

Lecture, Saturday 10:15-10:30

PRECISION IN ASTROMETRY AND PHOTOMETRY: AN AMATEUR APPROACH, Bernard Christophe,  65 Bld de Courcelles, 75008 Paris,France, e-mail: bchristo@club-internet.fr

When you study the rotation of asteroids it is necessary to get a great number of images of the star field. In fact, we have also access to a measure of the precisions in position and in magnitude. I would give some further explanations: Indeed, if a hundred images are recorded in the same area and if it is possible to measure in each picture a hundred stars by using sofware like IRIS or other, as well as the USNO catalog, we do get, for each star in common, a hundred measurements (10 000 measures in total). Consequently, it is possible to calculate the average and the rms of measured RA, De and Mag for each of the common stars. The average measurements could be used to update catalogs, whereas the rms value gives you an information on the obtained precision. I have performed this kind of survey with 100 images of an area surrounding the Asteroid 14923 1994TU3. Results, of course, are not "absolute" but depend on how images were taken and on the CCD used. I would  present some conclusions:  the survey brings about the following questions:

• Are the results in agreement with results of other observers?
• Why this kind of limits ?
• Are those linked only with the signal to noise ratio or with other parameters ?

Lecture, Saturday 10:30-10:45

ASTEROIDS AND COMET OBSERVATIONS. TOOLS AND PERSPECTIVES, Gyula Szabo, Szeged University, Dept. of Exp. Phys and Astron. Obs., H6720 Szeged, Dom ter 9, Hungary, e-mail: szgy@neptun.physx.u-szeged.hu

Tools of multicolor photometry of minor planets, spectrophotometric and morphologic monitoring of comets are discussed. For demonstration, we show the processes made on observations done at Calar Alto Observatory in 2000 and 2002. For asteroids, multicolor observations help us to extend the field of photometric examinations over the study of rotation properties, while possible colour modulations may refer to surface inhomogenties probable caused by a previous collosion. Asteroids of multiperiodic curves

may refer doubleness, or, alternatively, presence of non-forced precession caused by a collosion in the last some 100 thousend years. For comets, spectrophotometry and morphology can be studied in the same time with help of appropriate filter sequence selected. Production rates of different gas and dust components are determined, while the azimuthally renormalized images help us to reveal non-isotropic matter production. Gas and gas-to-dust ratios help us to classify the comets, and in some cases to  find objects of unusual behaviour as well. For example, in the case of the post-perihelion behaviour of C/2001 A2, we suggest an abnormally low quiescent activity intermitted by normal activity, instead of alternation of normal quiescent state and outbursts. Majority of these fields can be studied by amateur astronomers as well. With help of CCD-technics and modern image processing, the azimuthally renormalization of comet images seems to be the easiest field to be studied, where valuable results can be reached even without filters. With help of appropriate filters, the all other mentioned fields can be examed with amateur telescopes larger than about 30-40 cm. A project without need of observations aiming revealing the colour variations of asteroids is also suggested. Based on the asteroid observations of sky surveys, not only asteroids with detectable colour variations could be found, but the general probability function of colour modulation of asteroids could be calculated even when the average variation is below the accuracy of individual measurements. That kind of examinations require much computer work, but finally may lead to the statistic of asteroid collosions.

Lecture, Saturday 10:45-11:00

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Invited Lecture, Saturday 11:30-12:00

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Lecture, Saturday 12:00-12:15

STATUS OF ADAS, THE ASIAGO-DLR ASTEROID SURVEY, FROM DEC. 2000 TO MARCH 2002, Cesare Barbieri1, Giuliano Pignata2 _, Riccardo Claudi2, Ivano Bertini1, Sara Magrin1, Massimo Calvani2,Luciano Salvadori1, Gerhard Hahn3, Stefano Mottola3 , and Martin Hoffmann4, 1Department of Astronomy, University of Padova , 2Astronomical Observatory of Padova, 3DLR Institute of Space Sensor Technology and Planetary Exploration, Berlin (Germany), 4 Institute for Geology, Geophysics and Geoinformatics, Freie Universität Berlin (Germany)

 ADAS, the Asiago-DLR Asteroid Survey, is the joint program among the Department of Astronomy and Astronomical Observatory of Padova and the DLR Berlin, dedicated to the search of asteroids. The Minor Planet Center has attributed to ADAS the survey code 209. On the Web, ADAS is described in:

http://planet.pd.astro.it/planets/adas

The project is carried out since the end of December 2000 with the S67/92cm telescope at Asiago - Cima Ekar equipped with the SCAM-1 camera of DLR, in Time Delay Integration mode, in a strip from –5° to +15° around the celestial equator. The camera has a front illuminated Loral chip of 2048x2048 pixels of 15 micrometers each, covering a field of 49'x49' with a resolution of 1".4/pixel. 
This paper presents the main results obtained till March 15, 2002, when the telescope has been closed for a complete overhaul. ADAS will resume presumably at the end of June 2002.

Lecture, Saturday 12:15-12:30

Mike Kretlow, Occultation predictions of TNOs and other unusual asteroids

Lecture, Saturday 12:30-12:45

THE MAGNITUDE ALERT PROJECT (MAP), Gérard Faure, e-mail: gpmfaure@club-internet.fr

Many old numbered asteroids visually observed in the seventies and eighties showed discrepancies between predicted and observed magnitudes, which were be annually noted in a report in the Minor Planet Bulletin during many years.

Lawrence GARRETT, one of the coordinators of the Minor Planet Section of the ALPO (Association of Lunar and Planet Observers, in USA) proposed in 1996 an alert program which would inform observers of asteroids of suspected error immediately, rather then just publishing results annually, thank's to new use of Internet.

In this way, more observations would be obtained, allowing to better refine the suspected errors observed. The MAP was created by in late 1996. As member of the Minor Planet Section and member of the French network AUDE (Association des Utilisateurs de Detecteurs Electroniques, id est Electronic Detectors User's Association), I joined the MAP at the end of 1997 to contribute to its development and to relay AUDE measures to Lawrence GARRETT.  Together, Lawrence and myself share ideas on improving, publication, and promotion of the MAP.While Lawrence issue MAP alerts and reviews, I handle the data received from each observer in the MAP Database and furnish each month the MAP Observation Program. The objective of the MAP (Magnitude Alert Project) is to pursue the search and the follow-up of asteroids with magnitude discrepancy. The goal is to improve their H absolute magnitude, with an accuracy of about a tenth of magnitude. By the obtaining of visual or CCD magnitude measures, then by their global analysis for each asteroid, it is possible to revise the H magnitude which will permit the future calculations of more accurate ephemeride V magnitudes. Despite the difficulties to obtain asteroid magnitudes measures, notably by the lack of very accurate star catalogs, this Amateur Project permitted up to now to find more than two hundred asteroids with errors of magnitude apparently greater than 0.3 magnitude. The MAP is an opportunity to the visual and CCD amateur Observers to do an useful work with simple means. Two articles already have been published in the Minor Planet Bulletin in 1999 and 2001. They concerned 40 asteroids observed at least by three observers, often during two or more oppositions, with similar results for each of them. A revision of the H absolute Magnitude also was proposed.

Lecture, Saturday 12:45-13:00

Invited Lecture, Sunday 14:30-15:00

Andrea Milani, How to remove virtual impactors Lecture, Sunday 15:00-15:15

ON THE DISCOVERY OF FAINT TROJANS, Eric W. Elst, Holbach-Foundation, http://www.angelfire.com/id/ericelst/index.html, http://www.holbach-foundation.com/

Reflections are made about the discovery of new faint Trojans. It seems indeed that we are approaching an end in the discovering of  new Trojans, as far as a limiting magnitude of V=19.5 is envised. What could be the reason for this ? Are we really approaching an end, as a consequence that there should be a kind of gap between faint and faintest Trojans, assuming anyway the presence of « faintest » Trojans in L4 and L5, or is it just the consequence of the fact that present instruments are not reaching beyond the limiting magnitude from whereon we may expect  to discover again new Trojans. To answer this question we should first investigate the «theoretical » problem , assuming the existence of faint Trojans with absolute magnitudes larger than V=12.5 (present measure of completeness). Therefore we have studied the s.c. « cumulative distribution curves of the Jupiter Trojans », which are provided every month by the Minor Planet Center in Massachusetts (U.S.A.)

Let us therefore look at a typical example of a cumulative distribution curve (Jupiter Trojans, MPC, 2002  Mar. 28). Assuming that the larger asteroid-search-programs (LINEAR, LONEOS, Spacewatch, Catalina and NEAT) have covered the entire sky during a specific period, let us say, of about three year, then we may conclude from Fig.1 that during 1999-2001 all Trojans with absolute magnitudes less than V=12.5 have been discovered, since the location of the inflection point in the distribution  is a measure for completeness (Elst, 2001). However Trojans with high inclinations tend to be discovered much later during the searches, and may therefore have a small influence upon the aspect of the distribution curve. 

It is clear from this figure that presently discovering-completeness  has been obtained for Trojans with absolute magnitudes less than 12.5.  It follows also (by linear extrapolation) that about 200 more Trojans may be discovered  (if they should be present) in the range of V=12.5-13, assuming that Trojans are located  at nearly the same distance. Enhancing the limiting magnitude may therefore result in the discovery of  new faint Trojans.

Lecture, Sunday 15:15-15:30

Photoelectirc Photometry of minor planet 1998 WT_24,  Sergio Foglia,  Serafino Zani Astronomical Observatory, UAI Minor Planets Section, F. Bisleri 11, I-20148 Milano, Italy e-mail: s.foglia@libero.it

Photoelectric observations of Near Earth Asteroid 1998 WT ₂₄ were made on December 15/16, 2001 from Serafino Zani Astronomical Observatory located in Lumezzane (Italy, MPC Code 130) using a 40-cm Ritchey-Chretien telescope with a 1P21 single-channel photometer. A DCF-77.5 kHz radio signal receiver was used to determine Universal Time. During this night the geocentric distance of 1998 WT ₂₄ was only 0.013 A.U. and it was very difficult to find comparison's stars due to the fast motion of the minor planet. Observational's period cover 5 hours (from december 15, 21:00 U.T. to december 16, 02:00 U.T.); spectrum analisys of the obtained data gives a probable period of rotation of 4.558 hours. Observed amplitude in the V band was enlarged by the brightness of the comparison's star used.

The following is the obtained light curve reduced to the V(1,0) magnitude using the relation: where: V observed V magnitude,  r heliocentric distance, D geocentric distance, g slope parameter (0.15), b phase angle.

Lecture, Sunday 15:30-15:45

NEO astrometry from Church Stretton, Stephen Laurie, 10 Hazler Orchard, Church Stretton, Shropshire, SY6 7AL, UK, e-mail: slaurie@compuserve.com

This presentation reports on the NEO astrometry programme carried from observatory code 966 at Church Stretton in Shropshire, England.  The program is aimed at follow up observations of NEOs.  Targets are derived from either the MPC's Confirmation Page or lists of objects requiring follow up.  Observations on objects as faint as V=20.5 have been reported.  In the six months since the inception of the programme in November 2001 some 88 object nights have been submitted and NEO observations have appeared in 32 MPECs.  

The observatory at Church Stretton is a small amateur facility.  The main instrument is a 36cm C14 Schmidt-Cassegrain on an Astro-physics AP1200 go-to mount.  This has been used with an SBIG ST7E camera.  Using a 0.63 focal reducer the field of view is small at 9 x 6 arc minutes which presents problems with finding many confirmation page objects.  The camera will shortly be replaced with one based upon the 1K x 1K back illuminated CCD47-10 Marconi chip.  This will have the advantage of greater quantum efficiency, a field of view of 18 x 18 arc minutes and a 3 second download time.  Although the weather in Britain is generally cloudy there are typically 100 nights per year which are at least partially clear.  The Church Stretton site suffers from only moderate light pollution and the visual limiting magnitude is 6. 

The method of observation is to take a series of images of each object.  The exposure time is typically one minute but is reduced for the fastest moving objects so that the images do not trail.  Observations are processed using custom software written by the author.  This co-adds the images in two ways.  First the images are co-added normally and the astrometric grid is fitted to this combined image.  This combined image is then scaled and deducted from the other images to eliminate the stars and other non-moving objects.  These images are then shifted to allow for the motion of the object and combined using a median average.  The median processing eliminates cosmic rays, bright pixels and other artefacts.  What is left should be a blank image with just a dot where the asteroid is.  The position of the asteroid can be measured from this image.  Even for faint objects with S/N ratios of 5 the positional accuracy is ~0.5 arc seconds.  On occasions as many as 50 images have been combined by this method to yield a single measurement.              

Future plans centre around the new camera which will enable an extension of the follow up activities.  Observations of Confirmation Page objects in particular should be much more efficient.  The fast download time and low read out noise also makes it ideal for observing the fastest moving NEOs.  Another project is to commence searching for very fast moving NEOs with motion greater than 20 arc seconds per minute.  These objects are not currently being found by existing surveys.  Software is being developed to enable efficient detection such objects from trailed images.

Lecture, Sunday 15:45-16:00

MULTICOLOR COMETARY HEADS PHOTOMETRY, Giovanni Sostero , Remanzacco Observatory, P.zza Ten.Col.G. Miani, nr.31, 33047 Remanzacco, Italy; e-mail: Giovanni.sostero@elettra.Trieste.it

T he development of modern optoelectronic equipment has allowed many amateurs to contribute with their data in a novel way, into a number of astronomical topics. In cometary observations, two main fields of applications could be envisioned: photometry of comae and morphological studies. The author will review the preliminary results of long-term monitoring program on cometary heads photometry undertaken at a small backyard observatory. The instrumentation employed is a 0.3m, f/2.8 Baker-Schmidt camera and standard B, V, R, I photometric filters.

 Invited Lecture, Sunday 16:30-17:00

CORRECTORS FOR WIDE-FIELD CCD IMAGING: HOW TO DESIGN, MANUFACTURE AND USE THEM, ¥eljko Andrei¥,  Ru¥er Boškovi¥ Institute, div. of Materials physics, Thin Films Laboratory, Bijeni¥ka 54, Zagreb, Croatia, e-mail: andreic@rudjer.irb.hr

In recent time, many advanced amateurs and small astronomical facilties, have acces to 1 m-class telescopes. Most of these telescopes are Newtonians or clasicall Cassegrains, both types having parabolical primary mirrors. These instruments are either self-made, or are old instruments that are not primary research instruments anymore. To adapt them for CCD photography, one usually needs a field corrector which corrects the of-axis coma of the primary mirror and, at the same time, flattens the image plane so that the whole CCD sees a sharp image. If this lens system also shortens the focal length, it is usually called a telecompressor. It is supposed that such telescopes will be equipped with 1" CCDs, with a possible upgrade up to 2" in the years to come, as the prices of such cameras fall with time. Also, a point source (star!) image of about 30 m is taken as the upper limit of the acceptable image blur. Larger instruments (focal length of abut 3 m upwards, will have larger seeing blurs, so 50 m blur can be tollerated in such a case. A review of suitable corrector designs is presented, starting from a single lens field-flattener, up to a 5-lens multiple-glass focal corrector.
It is found that single-lens correctors have no sense in such an arrangement, as the image improvement is marginal or non-existent. At telescopes arround 0.5 m in diameter, field-flatteners do improve the image sharpness a little, but this efect is totaly overhelmed by the of-axis coma. The first usable corrector design is a two lens Ross corrector, which is usable at focal ratios of about F/4 or larger. For faster mirrors, it fails to produce small enough point images, althoug coma is still greatly reduced. The great advantage of a Ross corrector is that it is one-glass design with relaxed tolerances, so it can be produced by a skilled amateur optician. Many amateur telescope builder ere skilled enough to attempt such a work.
The first really good corrector is the three lens Wyne corrector, which is often used on larger telescopes. It is still one-glass design, but the tolerances of  individual lens surfaces are very tight. A skilled optitian is nedeed to produce such a corrector sucessfully.

Last, but not least, an example of modern multiple-glass, 5 lens focal reducer for an F/3 parabolic mirror is presented. Its tollerances are not so tight as the ones of  the Wyne corrector, but it requiers 3 different glasses, at least one of which is difficult to grind and polish. Again, a skilled optitian is the best choice for manufacturing of such a corrector.

Invited Lecture, Sunday 17:00-17:30

Korado Korlevi¥, Visnjan Observatory asteroids followup program 1995-2001

Lecture, Sunday 17:30-17:45

Mike Kretlow, Spectroscopic observations of comets with amateur means Lecture, Sunday 17:45-18:00

A NEW 60-CM TELESCOPE FOR THE ¥RNI VRH OBSERVATORY, B. Dintinjana, S. Mati¥i¥, H. Miku¥ , J. Skvar¥, ¥rni Vrh Observatory, 5274 ¥rni Vrh nad Idrijo, Slovenia, e-mail: herman.mikuz@Uni-Lj.si

Extensive sky coverage by professional NEO robotic surveys is producing asteroid discoveries at ever-deeper magnitudes.  Existing 36-cm telescope at ¥rni Vrh observatory is not sufficient anymore to be competive both for follow-up and our own discovery program – PIKA.  To comply with increasing technical requirements for successful asteroid observations, we built a 60-cm, f/3.3  Deltagraph telescope.   Optical components were made and tested at LOMO workshop and delivered by Astrooptik Company.  All other components, the telescope mount, optical tube, filter wheel and servo motor electronics was designed by us, based on experience of our previous projects. The telescope will be equipped WITH a BVR set of filters, and 1k x 1k thinned CCD. The telescope mechanics and electronics successfully passed all tests in the workshop.  We expect to put the telescope into regular operation in June 2002.

Lecture, Sunday 18:00-18:15

BUILDING THREE COMPACT-LOW COST 24' KLEVZOV TELESCOPES,                                           FOR NEO FOLLOW-UP, J. Nomen, S. Sanchez, J. Guarro, J. Rodriguez, A. Garcia,  M. Blasco,                                             Observatori Astronomic de Mallorca (OAM), Cami del Observatori s/n, 07144 Costitx, Mallorca, Spain, e-mail: astroam@bitel.es

In the latest years, the increment and efficiency of the big surveys are facilitating the discovery of  a greater number of NEO asteroids, in general, with fainter magnitudes. The traditional follow-up task made by observatories with medium aperture telescopes is resulting more and more difficult and, in many cases, is getting impossible. We are in front of a paradox in which many of the new discoveries of NEOs cannot be confirmed neither carry out the correct follow-up the next days by these observatories usually dedicated to such task, and is frustrating, therefore the improve in the equipment in many of those observatories with medium size telescopes is, commonly, costly and not easy to finance. The present project is born on the interest of the members of the observatory of Mallorca in arranging  some telescopes of greater aperture to continue with the work of NEO follow-up that traditionally has come carrying out the last years. For that, after a first experimental phase along 3 years, in which 3 Schmidt cameras of 40 cms were already built, practically only with their own means, the construction of 3 new telescopes of 61 cms has been initiated, also mostly undertaken with the optical, technical, mechanical, electronic and data processing resources of the team and the collaborators of the observatory.   The new telescopes have some very characteristic premises, that could turn out the project interesting and attractive also for other observatories with medium apertures and limited economic resources. Those goals are:  Very economical total cost, automated observation, low weight, very reduced size to fit in small domes, among others.  It's described and justified the design and construction, on the basis on the previous experience.

Poster session

Accuracy of the World asteroid CCD observations obtained by amateur and professional observatories in 1998-2001 yrs,  O.P.Bykov,  V.N.L'vov, I.S.Izmailov (1) and N.K.Sumzina(2), (1)  Pulkovo Astronomical Observatory, St.-Petersburg, Russia, (2)  Institute  of Applied Astronomy,  St.-Petersburg, Russia, e-mail: oleg@OB3876.spb.edu

 Positions of numbered planets received by the Minor Planet Center in 1999-2001 yrs  were automatically analysed by calculation of (O-C) residuals using the EPOS software package derived at the Pulkovo Observatory.  Over 1.5 millions individual positions obtained by professional and amateur observers were considered.  Values of "Mean error of a single observation" were computed for most of them,  characterizing            the accuracy of observations at the respective observatories.

The results will be shown in Tables representing observatories and countries.  Each Table contains the number of minor planets observed,  the number of analysed positions,  the available instruments and the star catalogues used for reduction.

Poster session

Pulkovo description of celestial body visible motion by means of Apparent Motion Parameters and fast orbit determination, O.P.Bykov, Pulkovo Astronomical Observatory, St.-Petersburg, Russia, e-mail: oleg@OB3876.spb.edu

The epoch of supremacy of CCD technique allows us to elaborate the new approach to the problem of observations, preliminary orbit determination and identification of any celestial body moving on the background of stars.  The fundamental base for such approach is the Classic Laplacean Method of orbit determination and its development created by Dr. A.A.Kiselev and his colleagues at the Pulkovo Observatory.Our orbital method was named the Apparent Motion Parameters method (the AMP method).  For its realization we must calculate from close crowded CCD asteroid observations distributed on a short topocentric arc of next parameters, namely coordinates (RA, DEC), angular topocentric velocity (mu) and acceleration (dmu),  positional angle (psi) and curvature (C) of visible asteroid's trajectory at given moment of observations.Due to the accurate star catalogues and computers one can calculate several astrometric positions of any celestial object and its angular velocity (mu, psi) by means of statistical processing of the set of object's coordinates almost in a real-time of CCD observations. These four parameters (namely RA, DEC, dRA/dt and dDEC/dt or mu and dmu)  are usually enough to determine its circular or parabolic preliminary orbit which may be useful for identification of observed object or for ephemeris service during several close nights or weeks.  Other parameters (dmu) and (C) if they may be calculate with good accuracy from obtained CCD observations can allowe us to determine an elliptical orbit.  In this manner we can investigate each CCD frame for the search of small Solar system bodies during their CCD observations.The algorithms and software were developed in Pulkovo observatory for the fast analysis of any CCD frame where the moving celestial objects were detected.  Examples of our approach will be presented in Tables. Also due to this approach we can get new information as "by product" of dominating astrophysical CCD observations.

Poster session

THE MINOR BODIES ASTROMETRY AND PHOTOMETRY AT THE ASTRONOMICAL OBSERVATORY IN MODRA – RESULTS AND EXPERIENCES , Štefan Gajdoš, Adrián Galád, Leonard Kornoš, Juraj Tóth, Jozef Világi, Pavol Zigo, Astronomical Institute, Faculty of Mathematics, Physics and Informatics,  Comenius University, Mlynská dolina 1, 842 48 Bratislava, Slovak Republic

A summary of both minor bodies astrometry and photometry programs at the Astronomical Observatory (AO) in Modra is presented. Brief results of astrometry, including the NEO follow-up and confirmation program are highlighted, as well as some experiences from a "small" observatory are added. Recently, an intented effort towards minor planets photometry is expended, with the aim of NEOs investigation. Some preliminary results based on our new photometry software were prepared. We plan to renew the aparture photometry of comets, too.

Poster session

PULKOVO EPOS SOFTWARE FOR ASTEROID AND COMET EPHEMERIDES, THEIR IDENTIFICATIONS AND TESTING OF OBSERVATIONS", V.N.L'vov,  R.I.Smekhacheva and S.D.Tsekmejster, Pulkovo Astronomical Observatory, Saint Petersburg, Russia, e-mail: ceresp@gao.spb.ru

EPOS (Ephemeris Program for Objects of Solar system) is a  software package  for  professional  and  amateur astronomers investigating the Solar system objects. It can serve for:

Calculation  of  the ephemerides  for various observations of the Solar system bodies with inclusion of the first and the second derivatives

• of spherical coordinates;
• Express   analysis   of   observations,   namely  their  accuracy
• estimation and rejecting the erroneous data
• Identification  of the observed objects with the catalog ones and
• searching for the new objects
• Preparation  of  illustrations  of  various  celestial  phenomena which would be used in education and enlightenment.

The Windows version of the EPOS software is under constraction now.

Poster session

The Observing Campaign at the Davidschlag Observatory, Erich Meyer and Herbert Raab,  Davidschlag Observatory, Astronomical Society of Linz, Austria, e-mail: herbert.raab@ris.at

The private observatory in Davidschlag, near Linz, Austria, was founded and built by two amateur astronomers, Erich Meyer and Erwin Obermair. Soon after construction works were completed in 1978, we  prepared for astrometric observations of minor planets. The first precise positions of a minor planet were accepted by the Minor Planet Center in 1979, and the observatory was rewarded with the observatory Code 540.
In 1982, a 0.3m f/5.2 Schmidt-Cassegrain replaced the 0.3m f/4.4 Newtonian reflector. In 1993, a CCD camera replaced photographic films. With the new detector, and the "Astrometrica" software that we have developed to carry out our astrometric campaign, we were able to participate in follow-up observations of NEOs. A computer-controlled 0.6m f/3.3 reflector was put into service in 1999.

The high rate of NEO discoveries in the past years require intensive follow-up observations (Ticha et al., 2000) which are carried out by a small number of professional observatories as well as a amateur astronomical sites. But while new discoveries, posted on the NEO Confirmation Page, receive high attention by the NEO community, later follow-up and arc-extending observations are frequently neglected.  As a result, many NEOs are observed over a very short arc only, and the orbital elements are therefore highly uncertain, making a targeted recovery at a subsequent apparition very difficult, or even impossible. Recognizing the need for late follow-up, the our observing campaign concentrates on arc-extending observations of NEOs. Many of these minor planets were in the range of 19mag to 21mag, with the faintest target around 22mag only. It should be noted that the sky-plane uncertainty of a single-apparition asteroids at any given time is approximately inversely proportional to the square of the observed arc. Doubling the observed arc therefore reduces the uncertainty in the position of the minor planet at any later time approximately by a factor of four. With these arc extensions, the sky-plane uncertainty for further observations, at a future recovery opportunity, or for a precovery search on archive images, is therefore significantly reduced.

Poster session

JOHANN PALISA, THE MOST SUCCESSFUL VISUAL DISCOVERER OF MINOR PLANETS, Herbert Raab, Davidschlag Observatory, Astronomical Society of Linz, Austria, e-mail: herbert.raab@ris.at

During MACE 2002, a trip to the remnants of the old Navy Observatory in Pola is scheduled. Among minor planet observers, this observatory is mostly known for the work of Johann Palisa. To provide some background for the trip to Pola, a short biography of Johann Palisa is provided.
In 1872, Palisa became director of the Austrian Naval Observatory in Pola. In 1880, Palisa gave up his position as the head of the Naval Observatory and accepted an employment as night assistant at the new observatory in Vienna. Here, he was able to routinely use the large 68cm refractor, at that time the largest telescope in the world. Palisa discovered further 93 asteroids at Vienna, all by visual observations. With 121 minor planets, Palisa is still the most successful Austrian discoverer of asteroids, as well as the most successful visual discoverer in the history of minor planet research.

Poster session

CCD MONITORING OF COMET C/2000 WM1 ( LINEAR ),  J. Rodríguez, S. Sánchez, A. García, M. Blasco, M. A. Villalonga, J.Guarro, J. Nomen, Observatorio Astronomico of Mallorca Team
 

The evolution and changes on the coma and tail of Comet C/2000 W1 (LINEAR) are shown on several CCD images obtained during Feb. 17 2001 until Dec. 13 2001.

Poster session

LONG-TERM CCD MONITORING OF COMET C/1999 S4 ( LINEAR ), J. Rodríguez, S. Sánchez, A. García, M. Blasco, M. A. Villalonga, J.Guarro, J. Nomen, Observatorio Astronomico of Mallorca Team

The results from the analysis of the extensive CCD photometry that we have obtained during the long-term monitoring (from its discovery until its break-up) of comet C/1999 S4 ( linear ) are presented here. Our observations show that the comet did not always behave as expected: it showed activity ahead of time and in the end became fainter instead of brighter as it aproached perihelion. A sequence of images and curves are shown.

Poster session

PHOTOMETRY OF SELECTED ASTEROIDS WITH NO PREVIOUS PHOTOMETRIC DATA, Peter Szekely,  University of Szeged, Department of Experimental Physics and Astronomical Observatory, H-6720,Szeged, Dom ter 9, Hungary, e-mail: pierre@pluto.physx.u-szeged.hu

We present new unfiltered CCD observations of 14 moderately faint main-belt asteroids with no previous photometric data in the literature carried out between June, 2001 and February, 2002. The achieved accuracy widely varies between 0.05 and 0.2 magnitude depending on atmospheric conditions and used telescopes. Used instruments were the 0.4 meter Cassegrain telescope equipped with SBIG ST-9E CCD-camera of the Szeged University, Hungary, and the 60/90/180 cm Schmidt telescope equipped with Photometrics AT200 CCD camera of the Piszkéstet¥ Station of Konkoly Observatory, Hungary.

The obtained amplitudes (A) and synodic periods (P) are the followings:

469 Argentina A=0.14m, P=8.2h ?;

546 Herodias A=0.1m, P=8.450h;

549 Jessonda A>0.15m; P=?

551 Ortrud A<0.1m;

756 Lilliana A=0.56m, P=4.683h;

894 Erda A<0.1m;

1108 Demeter A<0.15m;

1170 Siva A<0.1m, P<3.12h ?;

1286 Banachiewicza A>0.4m, P>2.4h ?;

1400 Tirela A=0.55m, P=15h;

1503 Kuopio A=0.77m, P=9.96h;

1506 Xosa A=0.17m, P=6.7h ?;

1695 Walbeck A=0.34m, P=8.93h ?;

3682 Welther A=0.36m, P=3.718h.

.Poster session

THE STARKENBURG OBSERVATORY NEO FOLLOW-UP PROGRAMME, R. Stoss, M. Busch, S. Klügl, F. Hormuth, E. Schwab and various sporadic observers

In 1995 the first CCD astrometric measures of NEOs have been made from Starkenburg Observatory, Heppenheim. Since then more than 270 NEOs have been observed and their positions reported to the Minor Planet Center (MPC).

Beside these routine follow-up observations of numbered or provisionally designated objects starting in 1998 we focused on the confirmation of newly discovered NEO candidates posted on the MPC's NEO Confirmation Page (NEOCP). In the first four years of this work (1998-2001) a large number of NEO candidates was confirmed and astrometry reported. This resulted in more than 200 publications in Minor Planet Electronic Circulars (MPECs) for NEOs and other unusual objects as well as several International Astronomical Union Circulars (IAUCs) in cases where the NEO candidates from the NEOCP turned out to be comets.

The third part of our work are recovery attempts of single-opposition NEOs. Six Recoveries have been achieved until now, from this 2 Atens, 2 PHA-Apollos, 1 Amor and 1 otherwise unusual object.

A summary of this work is presented on the Starkenburg Obs. website at: http://www.starkenburg-sternwarte.de/

Poster session

THE DLR-ARCHENHOLD NEAR-EARTH OBJECTS PRECOVERY SURVEY - DANEOPS, Hahn, G.J., Erikson, A., Mottola, S., Hoffmann, M., Doppler, A., Gnädig, A., *Stoss, R ., Busch, M., Lagerkvist, C.-I., Oja, T., Warell, J., and Karlsson, O. G.J. Hahn (DLR), A. Erikson (DLR), S. Mottola (DLR), M. Hoffmann (DLR), A. Doppler (Archenhold Obs.), A. Gnädig (Archenhold Obs.), R. Stoss (Starkenburg Obs.), M. Busch (Starkenburg Obs.), C.-I. Lagerkvist (Uppsala Astron. Obs.), T. Oja (Uppsala Astron. Obs.), J. Warell (Uppsala Astron. Obs.), O. Karlsson (Uppsala Aston. Obs.)

Archive search for precovery positions of newly discovered Near-Earth Objects (NEOs) has turned out to a powerful tool, in complement to the necessary astrometric follow-up work, to improve the orbit determination of these objects. The DLR-Archenhold Near-Earth Objects Precovery Survey (DANEOPS) programme is dedicated to archival searches and routinely scans the logs (dates, plate coordinates) of more than 300,000 photographic and/or digitized images and CCD frames as soon as reliable orbits render the needed ephemeris calculations accurate enough to yield acceptable search regions. These ephemerides are based on n-body orbital integrations, taking into account the perturbations of all major planets and the Earth-Moon system as separate bodies.
Since its start in 1999 for more than 100 NEOs precovery positions at one or sometimes several earlier apparitions could be identified and the corresponding astrometric positions measured and submitted to the Minor Planet Center (MPC) for orbit improvement.
In addition to the archive search, dedicated observing campaigns to attempt recoveries of predicted returns of one-opposition NEOs have organized and successfully performed.
All our results are displayed on the DANEOPS website at http://earn.dlr.de/daneops/ which shows predictions, actually measured positions, the used images (whenever possible) and a link to the published orbit, usually a Minor Planet Electronic Circular (MPEC) issued by the MPC.