Transcript The astronomy in Mexico, South Africa, Chile, Canada and Spain, in

EURONEAR, an international
project to study Near Earth
Asteroids
Ovidiu Vaduvescu
Conferinta Diasporei - Workshop Astronomie
22-24 Sep 2010
Bucharest, Romania
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Why Near Earth Asteroids (NEAs)?
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Because this was my proposed subject for my association with IMCCE and
Dr. Mirel Birlan;
Because asteroids and Solar System dynamics were the subjects of my
Romanian PhD with the regretted Prof. Dr. Arpad Pal of Babes Bolyai Univ,
Cluj Napoca (1993-1997);
Because Europe is almost null in NEA survey work, while the Americans
own 99.8% of discoveries of the actual NEA population!
Because I liked a lot the movie “Deep Impact” and I really hope to be able
to save the world 
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MBAs, NEAs, PHAs and VIs
 Main Belt Asteroids (MBAs) are minor planets moving between the orbits of
Mars and Jupiter, between about 3.1 and 3.5 AU (astronomical units). Since
1800 (the discovery of Ceres), there are more than half million MBAs known
today!
Near Earth Asteroids (NEAs) are defined as the asteroids with a perihelion
distance (q) less than 1.3 AU. There are more than 7100 NEAs known today.
 Potentially Hazardous Asteroids (PHAs) are the NEAs having a Minimum
Orbital Intersection Distance (MOID) less than 0.05 AU and the absolute
magnitudes (H) less than 22 mag, which corresponds to objects larger than
about 150m. There are more than 1100 PHAs known today.
 Virtual Impactors (VIs) are the PHAs whose present orbital uncertainty result
in a non-zero impact probability with the Earth in the near future. There are
about 100 VIs known today, most of them very faint and inaccessible to existing
~1m class surveys.
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What is EURONEAR?
European Near Earth Asteroids Research
A project which envisions to
establish a coordinated network
to follow-up, recover and discover
Near Earth Asteroids (NEAs) and
Potentially Hazardous Asteroids
(PHAs) using two automated
dedicated 1-2m telescopes located
in both hemispheres and other
facilities available to the members
of the network.
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The Network / Observing runs
Includes mostly 1-2m telescopes accessed via regular observing proposals:
 Pic du Midi 1m, France (9n, 2006)
 York University 0.6m, Canada (10n, 2002, 2003 & 2004)
 OCA Cerro Armazones 0.84m, Chile (3n, 2007)
 Las Campanas Swope 1m, Chile (10n, 2008 & 2009)
 Cerro Tololo 1m, Chile (5n, 2008)
 La Silla ESO 1m, Chile (3n, 2007)
 Haute Provence 1.2m, France (11n, 2007, 2010)
 INT 2.5m, La Palma (10n, 2009 & 2010)
 La Silla ESO/MPG 2.2m, Chile (2n, 2008)
 INT 2.5m & ESO/MPG 2.2m (data mining)
 CFHTLS 3.6m, Hawaii (data mining)
 Subaru 8.3m (data mining, to come soon)!
 Vasile Urseanu Observatory 0.3m 
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Follow up, Recovery and Discovery of NEAs and MBAs
Sample of an ESO2m field showing three MBAs and probably one new NEA.
The series of frames represents 8 image taken at a small interval (cca 1 min).
The search of known and new asteroids and measurement (astrometry and
photometry) could be performed by an amateur or student assisted by the
Astrometrica program. Alternatively, some automated pipeline could be used.6
Results: Observations in the Network
 224 NEAs, PHAs and VIs followed-up and reported to Minor Planet Centre
(MPC) during the last 4 years in about 10 runs using mostly 1-2m class
telescopes;
 Probably one NEA was discovered in one ESO2m field on 12/13 March 2008,
unfortunately being lost due to late inspection.
 About 500 known MBAs were observed incidentally in the 2m fields and
reported to MPC;
 About 500 new MBAs were discovered in the ESO2m, INT 2.5m and Swope
1m observed fields, all being reported to MPC, from which 58 became
EURONEAR official discoveries;
 We are the first Romanian asteroid discoverers, the team being formed
mostly by Romanian students and amateurs;
 Part of EURONEAR, two Romanian students were the first to observe in Chile
and La Palma.
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Results: Accurate Astrometry
Observed minus calculated (o-c) residuals for EURONEAR NEA observations (left)
compared with residuals of the same asteroids observed by all other major
surveys. EURONEAR data appear better confined around zero, having a standard
statistical error under 0.25” (Birlan, Vaduvescu, Tudorica et al, 2010)
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Results: Data Mining
Besides new observations (subject of time allocation and telescope access), data
mining of image archives (scanned photographic plates or CCD) represents
another investigation tool of EURONEAR.
Given one archive represented by a simple observing log, we look for
serendipitous encounters of known NEAs whose positions could be measured
and used to ameliorate the orbits.
PRECOVERY, a software accessing SKYBOT server at IMCCE facilitates this work.
Until now, we studied the following archives:
 Bucharest plates 38cm refractor: ~10,000 2x2 deg plates; no apparitions due
to low mag limit V~13 (Vaduvescu, Curelaru, Birlan et al, 2009)
 CFHT Legacy Survey: ~25,000 Megacam 1x1 deg images, cca 500
encounters (Vaduvescu, Tudorica, Birlan et al, 2010)
 ESO/MPG 2.2m WFI (100,000 34’x34’ images) and INT 2.5m (230,000
33’x34’ images): work in progress (in a team of 10 students and amateurs);
 Subaru 8.3m SuprimeCam 34’x27’ (next project, collaborators welcomed)
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Results: Orbital Amelioration
Astrometric positions of NEAs (from data mining or new observations) serve to
ameliorate of the asteroid orbits (some of them insecure with large errors due to
small number of observations or interval).
We could classify the results (Vaduvescu et al, 2010):
 Extended arcs at first opposition (Precoveries = serenditipitous observations
at one opposition before discovery date – from data mining only);
 Extended arcs at last opposition (Recoveries at one new opposition – from
data mining or new observations);
 Refined arcs at one intercalated oppositions (Recoveries – from data mining);
 Refined very small arcs (a few weeks);
 Extended arcs at second opposition (major recoveries).
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Results: Photometry of NEAs
Long time photometry – a few hrs in
successive nights, eventually from
multiple coordinated stations.
Some physical parameters could be
derived from photometry:
 Determination of asteroid rotation
periods (with accuracy of ~0.001 hr)
 Discovery of binary systems (yes,
many asteroids are double systems)!
This method require dedicated time (a
few successive nights and good
weather) and relatively large telescope
(preferably 2m) to achieve good
precision (~0.01mag)
Birlan, Vaduvescu, Galad et al, 2010
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My Dream: 1-2 Dedicated Facilities
Motto: “With only one flower, one can not make the spring” 
 Feb 2008: Five institutional members (IMCCE France, Armagh Observatory
UK, Turku Observatory Finland, AICR the Czech Republic, and IA UCN Chile)
sent an FP7 application to support EURONEAR for 4 years by the EU. The
proposal passed the threshold (with a score 10/15) but could not be financed
due to insufficient funding;
 Sep 2010: A new FP7 proposal is intended to be submitted at the end of
2010 on behalf of 15 institutions from 10 EU countries actually constituting
our EURONEAR Consortium. Presently, we are aiming to submit a 10-20 ME
proposal to buy a new 2.3m telescope to be installed in Canary to devote to
EURONEAR. An additional 1m telescope, preferably in the South is also
envisioned to serve the original aims of our project.
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Collaborators
 EURONEAR Team: M. Birlan, P. Rocher, J. Berthier, F. Colas, V. Lainey
(IMCCE Paris), P. Pravec & A. Galad (Ondrejov), D. Asher (Armagh, UK), R.
Rekola (Turku, Finland), etc;
 About 15 amateurs and students from Romania: A. Tudorica, A. Sonka, R.
Toma, M. Badea, T. Badescu, M. Popescu, I. Comsa, L. Curelaru, M.
Constantinescu, D. Vidican. C. Opriseanu, C. Vancea, D. Dumitru, A. Paraschiv,
D. Lacatus (SARM, Bucharest Astroclub, Univ. of Bucharest, Cluj Napoca), etc;
 Former students and colleagues from Chile: F. Pozo, A. Barr, P. Longa, J. P.
Colque, Prof. E. Unda-Sanzana, etc;
 Present colleagues and students from Spain: J. Skvarc & T. Agocs (ING), J.
Licandro (IAC Tenerife), J. L. Ortiz & R. Duffard (IAA Granada), etc;
 Others welcomed!
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References
http://www.ovidiuv.ca/papers/
Vaduvescu et al, 2006-2010: About 40 Minor Planet Circulars (see MPC or ADS)
Vaduvescu, O., 2006, RoAJ 15, 171 & 14, 199
"Observing Near Earth Asteroids with a Small Telescope"
Vaduvescu, O. et al., 2008, Pl. Sp. S. 56, 1913
"EURONEAR: First Results"
Vaduvescu, O. et al., 2009, Astron. Nachr. 330, 7, 698
"EURONEAR: Data mining of asteroids and Near Earth Asteroids"
Birlan, M., Vaduvescu, O., et al., 2010, A&A 511, A40
"More than 160 near Earth asteroids observed in the EURONEAR network"
Vaduvescu, O., et al. 2010, submitted to AN (June 2010)
"Mining the CFHT Legacy Survey for known Near Earth Asteroids"
Pravec, P., et al., 2010, Nature 466, 1085
"Asteroid pairs formed by rotational fission"
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