J/A+A/665/A66 Calern Asteroid Polarisation Survey (Bendjoya+, 2022)
The Calern Asteroid Polarisation Survey:
An updated catalogue of asteroid polarimetric data.
Bendjoya P., Cellino A., Rivet J.-P., Devogele M., Bagnulo S., Abe L.,
Vernet D., Gil-Hutton R., Venezian A.
<Astron. Astrophys. 665, A66 (2022)>
=2022A&A...665A..66B 2022A&A...665A..66B (SIMBAD/NED BibCode)
ADC_Keywords: Minor planets
Keywords: minor planets - asteroids: general - catalogs
Abstract:
The Calern Asteroid Polarimetric Survey (CAPS), a collaboration
between the INAF Astrophysical Observatory of Torino (Italy) and the
Observatoire de la Cote d'Azur (Nice, France), has produced new
asteroid polarimetric data for a number of years, and is one of the
most important, currently active projects of asteroid polarimetry.
The purpose of this paper is to make public the CAPS data collected
thus far, to explain the adopted techniques of data reduction and
computation of phase-polarisation curves for the measured objects, and
explain, by means of some examples, the importance of the CAPS
database.
The pipeline of data reduction has been recently updated and made as
automatic as possible, using numerical algorithms developed
specifically for the purposes of CAPS. The derivation of
phase-polarisation curves for the observed asteroids is done using
established criteria and algorithms that have recently been slightly
improved, and are also summarised in this paper.
The CAPS catalogue is a steadily growing source of information which
can be exploited for different purposes, including, but not limited
to, an updated calibration of the relations existing between different
polarimetric parameters and the geometric albedo of the objects, and a
study of classes of objects that can be most easily identified by
means of their polarimetric properties. These subjects will be more
specifically discussed in separate papers.
Asteroid polarimetry data nicely complement the results of other more
commonly used techniques, including visible and IR photometry and
spectroscopy. CAPS contains a lot of much-desired information about
physical properties, which can hardly be inferred by means of other
techniques.
Description:
The Calern Asteroid Polarimetric Survey (CAPS), a collaboration
between the INAF, Astrophysical Observatory of Torino (Italy) and the
Observatoire de la Cote d'Azur (Nice, France) has produced new
asteroid polarimetric data for a number of years, and is one of the
most important, currently active projects of asteroid polarimetry. The
CAPS catalogue is a steadily growing source of information which can
be exploited for different purposes, including but not limited to an
updated calibration of the relations existing between different
polarimetric parameters and the geometric albedo of the objects, and a
study of classes of objects that can be most easily identified by
means of polarimetric properties. Until now unpublished data, from the
CASLEO (Complejo Astronomico El Leoncito) survey are also added to
the catalogs.
The CAPS catalog includes the results obtained by the Calern Asteroid
Polarimetric Survey since the beginning of operations (August, 2018),
up to December, 2021. All the data collected for each object are
listed, specifying for each entry the object's identification
number, the epoch of observation (expressed as year, month, day and
fraction of day, the phase angle, the value of the measured Pr, its
error, and the filter used. As for the latter, it is most commonly the
standard V filter, but in several cases also the B, R and I filters of
the Johnson-Cousin system have been used.
The CASLEO catalog lists, using the same format adopted for the CAPS data,
a number of unpublished polarimetric measurements of asteroids obtained
between 1995 and 2004, plus a small number of measurements obtained in
2013, using the 2.15m telescope of the Complejo Astronomico El Leoncito
(CASLEO), managed by the Universities of La Plata, Cordoba and San
Juan (Argentina), and the Argentinian scientific and technical research
council (CONICET).The U, B, V, R and I filters are those of the
Johnson-Cousin system.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 35 600 List of asteroids with data in tables
caps.dat 67 2050 The CAPS data (table A1)
casleo.dat 67 1129 The CASLEO data (table A2)
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See also:
B/astorb : Orbits of Minor Planets (Bowell+ 2014-)
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- Id Asteroid number
8- 27 A20 --- Name Asteroid name
29- 30 I2 --- NT1 ? Number of measurements in CAPS data
(table A1)
34- 35 I2 --- NT2 ? Number of measurements in CASLEO data
(table A2)
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Byte-by-byte Description of file: caps.dat casleo.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
5- 10 I6 --- Id Asteroid Identification
17- 26 A10 "date" Date Observation date, YYYY-MM-DD
31- 35 F5.3 d Frac Fraction of the Day
39- 44 F6.2 deg alph Phase angle
49- 53 F5.2 % Pr Linear degree of Polarisation
58- 62 F5.2 % e_Pr Error on Linear degree of Polarisation
67 A1 --- Filter [UBVRI] Filter UBVRI in Johnson-Cousin system
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Acknowledgements:
Philippe Bendjoya, bendjoya(at)oca.eu,
Univ. Cote d'Azur-Obs. Cote d'Azur-CNRS
(End) Philippe Bendjoya [Obs. Cote d'Azur], Patricia Vannier [CDS] 05-Sep-2022