J/A+A/583/A59 Gaia-FUN-SSO network. Apophis campaign (Thuillot+, 2015)
The astrometric Gaia-FUN-SSO observation campaign of 99942 Apophis.
Thuillot W., Bancelin D., Ivantsov A., Desmars J., Assafin M., Eggl S.,
Hestroffer D., Rocher P., Carry B., David P., Abe L., Andreev M.,
Arlot J.-E., Asami A., Ayvasian V., Baransky A., Belcheva M., Bendjoya P.,
Bikmaev I., Burkhonov O.A., Camci U., Carbognani A., Colas F.,
Devyatkin A.V., Ehgamberdiev Sh.A., Enikova P., Eyer L., Galeev A.,
Gerlach E., Godunova V., Golubaev A.V., Gorshanov D.L., Gumerov R.,
Hashimoto N., Helvaci M., Ibryamov S., Inasaridze R.Ya., Khamitov I.,
Kostov A., Kozhukhov A.M., Kozyryev Y., Krugly Yu.N., Kryuchkovskiy V.,
Kulichenko N., Maigurova N., Manilla-Robles A., Martyusheva A.A.,
Molotov I.E., Nikolov G., Nikolov P., Nishiyama K., Okumura S.,
Palaversa L., Parmonov O., Peng Q.Y., Petrova S.N., Pinigin G.I.,
Pomazan A., Rivet J.-P., Sakamoto T., Sakhibullin N., Sergeev O.,
Sergeyev A.V., Shulga O.V., Suarez O., Sybiryakova Y., Takahashi N.,
Tarady V., Todd M., Urakawa S., Uysa O., Vaduvescu O., Vovk V., Zhang X.-L.
<Astron. Astrophys. 583, A59 (2015)>
=2015A&A...583A..59T 2015A&A...583A..59T (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Minor planets ; Positional data ; Ephemerides
Keywords: astrometry - minor planets, asteroids: individual - ephemerides
Abstract:
Astrometric observations performed by the Gaia Follow-Up Network for
Solar System Objects (Gaia-FUN-SSO) play a key role in ensuring that
moving objects first detected by ESA's Gaia mission remain recoverable
after their discovery. An observation campaign on the potentially
hazardous asteroid (99942) Apophis was conducted during the
asteroid's latest period of visibility, from 12/21/2012 to 5/2/2013,
to test the coordination and evaluate the overall performance of the
Gaia-FUN-SSO .
The 2732 high quality astrometric observations acquired during the
Gaia-FUN-SSO campaign were reduced with the Platform for Reduction of
Astronomical Images Automatically (PRAIA), using the USNO CCD
Astrograph Catalogue 4 (UCAC4, Cat. I/322) as a reference. The
astrometric reduction process and the precision of the newly obtained
measurements are discussed. We compare the residuals of astrometric
observations that we obtained using this reduction process to data
sets that were individually reduced by observers and accepted by the
Minor Planet Center.
Description:
This table gives the astrometric measures issued from the observations
of the Near-Earth Asteroid (99942) Apophis done during the last
apparition in 2012-2013. All these data are issued from a campaign of
observation carried out by the Gaia Follow-Up Network for Solar System
Objects (Gaia-FUN-SSO).
This table (table3) provides two set of data
1. table3a lists two sets of records with a format identical to the
Minor Planet Center usual format with one extra decimals in right
ascension and declination (MPC full precision format):
- Records from 1 to 2103: new measures not delivered to the Minor
Planet Center
- Records from 2014 to 2732: 629 measures already delivered to MPC but
issued from a new reduction of the images using the UCAC4 catalog and
the PRAIA astrometry software.
2. In subdirectory frames: a set of 2732 files TXXX_YYY with:
- XXX = IAU code of the site
(see http://www.minorplanetcenter.net/iau/lists/ObsCodesF.html)
- YYY = file number from 1 to N, where N is the total number of
Apophis positions for that site.
These files, corresponding to 2732 CCD frames, give the X Y measures
of the Near-Earth Asteroid (99942) Apophis and of the reference stars
for each frame. These values can allow an astrometric re-reduction
with other stellar catalogues, such as the Gaia catalogue. In these
files, the data format is as follows:
- The first entry regards to Apophis.
- The remaining entries regard to the used UCAC4 reference stars.
All the entries RA,DEC, X, Y, DJ can be accessed with the Fortran
format: (2(1x,f13.9),2(1x,f7.2),1x,f16.8).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3a.dat 69 2732 Astrometric measurements of Apophis
frames/* . 2732 *Individual CCD frames (X and Y measurements)
--------------------------------------------------------------------------------
Note on frames/*: files labeled TXXX_YYY.dat, where XXX is the IAU code of the
site, and NNN the total number of Apophis positions for that site.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3a.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Name Asteroid name
7 A1 --- Recep [C] Code for receptor (1)
9- 25 A17 "date" Date Date of observation (YYYY/MM/DD.dddddd)
27- 28 I2 h RAh Right ascension (J2000)
30- 31 I2 min RAm Right ascension (J2000)
33- 38 F6.3 s RAs Right ascension (J2000)
40 A1 --- DE- Declination sign
41- 42 I2 deg DEd Declination (J2000)
44- 45 I2 arcmin DEm Declination (J2000)
47- 51 F5.2 arcsec DEs Declination (J2000)
53- 55 A3 --- Obs Observatory code (2)
57- 69 A13 --- FileName Name of the file with CCD frames in
subdirectory frames
--------------------------------------------------------------------------------
Note (1): In the MPC format this code can describe the receptor as explained at
this address http://www.minorplanetcenter.net/iau/info/OpticalObs.html
Here C stands for CCD.
Note (2): The observatory codes used in this table are the Minor Planet Center
observatory codes which are listed at:
http://www.minorplanetcenter.net/iau/lists/ObsCodes.html
--------------------------------------------------------------------------------
Byte-by-byte Description of file: frames/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
3- 14 F12.9 h RAhours Right ascension in decimal hours
16- 28 F13.9 deg DEdeg Declination in decimal degrees
30- 36 F7.2 pix Xpos X coordinate in pixels
38- 44 F7.2 pix Ypos Y coordinate in pixels
46- 61 F16.8 d JD UTC in Julian Date
--------------------------------------------------------------------------------
Acknowledgements:
William Thuillot, William.Thuillot(at)obspm.fr
(End) Patricia Vannier [CDS] 19-Aug-2015