J/AJ/157/120 TNOs and Centaurs observed within the DES (Banda-Huarca+, 2019)
Astrometry and occultation predictions to Trans-Neptunian and Centaur objects
observed within the Dark Energy Survey.
Banda-Huarca M.V., Camargo J.I.B., Desmars J., Ogando R.L.C.,
Vieira-Martins R., Assafin M., da Costa L.N., Bernstein G.M.,
Carrasco Kind M., Drlica-Wagner A., Gomes R., Gysi M.M., Braga-Ribas F.,
Maia M.A.G., Gerdes D.W., Hamilton S., Wester W., Abbott T.M.C.,
Abdalla F.B., Allam S., Avila S., Bertin E., Brooks D., Buckley-Geer E.,
Burke D.L., Carnero Rosell A., Carretero J., Cunha C.E., Davis C.,
De Vicente J., Diehl H.T., Doel P., Fosalba P., Frieman J.,
Garcia-Bellido J., Gaztanaga E., Gruen D., Gruendl R.A., Gschwend J.,
Gutierrez G., Hartley W.G., Hollowood D.L., Honscheid K., James D.J.,
Kuehn K., Kuropatkin N., Menanteau F., Miller C.J., Miquel R., Plazas A.A.,
Romer A.K., Sanchez E., Scarpine V., Schubnell M., Serrano S.,
Sevilla-Noarbe I., Smith M., Soares-Santos M., Sobreira F., Suchyta E.,
Swanson M.E.C., Tarle G., (the DES Collaboration)
<Astron. J., 157, 120-120 (2019)>
=2019AJ....157..120B 2019AJ....157..120B (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Minor planets ; Photometry, ugriz
Keywords: astrometry - ephemerides - Kuiper belt: general - occultations -
surveys
Abstract:
Trans-Neptunian objects (TNOs) are a source of invaluable information
to access the history and evolution of the outer solar system. However,
observing these faint objects is a difficult task. As a consequence,
important properties such as size and albedo are known for only a small
fraction of them. Now, with the results from deep sky surveys and the
Gaia space mission, a new exciting era is within reach as accurate
predictions of stellar occultations by numerous distant small solar
system bodies become available. From them, diameters with kilometer
accuracies can be determined. Albedos, in turn, can be obtained from
diameters and absolute magnitudes. We use observations from the Dark
Energy Survey (DES) from 2012 November until 2016 February, amounting
to 4292847 charge-coupled device (CCD) frames. We searched them for all
known small solar system bodies and recovered a total of 202 TNOs and
Centaurs, 63 of which have been discovered by the DES collaboration as
of the date of submission. Their positions were determined using the
Gaia Data Release 2 (Cat. I/345) as reference and their orbits were
refined. Stellar occultations were then predicted using these refined
orbits plus stellar positions from Gaia. These predictions are maintained,
and updated, in a dedicated web service. The techniques developed here
are also part of an ambitious preparation to use the data from the
Large Synoptic Survey Telescope (LSST), that expects to obtain accurate
positions and multifilter photometry for tens of thousands of TNOs.
Description:
The DES is a survey that covers 5000 square degrees in the grizY bands
of the southern celestial hemisphere. Observations within the survey
are made with the Dark Energy Camera (DECam; Flaugher et al.
2015AJ....150..150F 2015AJ....150..150F), a mosaic of 62 2kx4k red-sensitive CCDs installed
on the prime focus of the 4 m Blanco telescope at the Cerro Tololo
Inter-American Observatory. The DECam has a field of view (FOV) of
3 square degrees and the wide-area survey images have, at a 10σ
detection level, a nominal limiting magnitude of r=23.34, with the final
co-added depth being roughly one magnitude deeper (Morganson et al.
2018PASP..130g4501M 2018PASP..130g4501M). Considering only those observations made during
the first three years of operation of the DES, the DECam acquired science
images from more than 69000 pointings or, more precisely, 4292847
individual CCD exposures in the five bands. This is an invaluable data
set to studies in several fields of astronomy (see Dark Energy Survey
Collaboration et al. 2016MNRAS.460.1270D 2016MNRAS.460.1270D), in particular, those related
to transient events and moving objects.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 118 128 Statistics from the reduction of TNOs and
Centaurs: main sources
table6.dat 118 13 Statistics from the reduction of TNOs and
Centaurs: extension sources
table7.dat 118 61 Statistics from the reduction of TNOs and
Centaurs: doubtful sources
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/584/A96 : Observations of 50 TNOs and Centaurs (Desmars+, 2015)
J/MNRAS/462/1351 : Outer satellites occultation predictions
(Gomes-Junior+, 2016)
http://www.darkenergysurvey.org/ : The Dark Energy Survey homepage
Byte-by-byte Description of file: table5.dat table6.dat table7.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Type Object type (TNO or Centaur)
9- 32 A24 --- ID Object identifier (1)
34- 39 F6.3 mag magavg [18.5/26.93] Average magnitude as obtained
from the bluest filter (2)
41- 45 F5.3 mag e_magavg [0.001/0.5]? Uncertainty in magavg
47 A1 --- leRA [>] Limit flag on e_RA
48- 55 E8.1 mas e_RA [53/5.3404e+07] 3σ uncertainty in the
ephemeris position in RA (3)
57 A1 --- leDE [>] Limit flag on e_DE
58- 66 E9.1 mas e_DE [10/2.72553e+08] 3σ uncertainty in the
ephemeris position in DE (3)
68- 74 F7.3 mas sigRA [0.053/833]? Standard deviation as obtained
from the observed position minus these from
the respective JPL ephemeris in RA
σαcosδ
76- 82 F7.3 mas sigDE [0.016/929]? Standard deviation as obtained
from the observed position minus these from
the respective JPL ephemeris in DE
σδ
84- 86 I3 s b_Exp [90/330] Minimum exposure time of the image
from which a position was obtained
88- 90 I3 s B_Exp [90/400] Maximum exposure time of the image
from which a position was obtained
92- 94 I3 --- Npos [1/438] Number of positions obtained
96- 98 I3 --- Ndet [1/467] Number of detections delivered by the
astrometric code (all positions,
no eliminations)
100-102 I3 --- Nim [1/670] Total number of images with exposure
times greater than or equal to 50 s
104-105 I2 --- o_gmag [1/44]? Number of magnitudes in g filter in
the DES database (4)
107-108 I2 --- o_rmag [1/72]? Number of magnitudes in r filter in
the DES database (4)
110-112 I3 --- o_imag [1/101]? Number of magnitudes in i filter in
the DES database (4)
114-116 I3 --- o_zmag [1/214]? Number of magnitudes in z filter in
the DES database (4)
118 I1 --- o_Ymag [1]? Number of magnitudes in Y filter in
the DES database (4)
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Note (1): Table 5 (main) considers those sources for which the 1σ
ephemeris uncertainty (σE) in both R.A./decl. is smaller than or equal
to 2" for TNOs and Centaurs and the number of observations (N) is greater than
or equal to 3. Table 6 (extension) considers those sources for which the
ephemeris uncertainty is 2"<σE=<12" and N≥5. Table 7 (doubtful)
considers the remaining sources.
Note (2): Bluest magnitude from the Dark Energy Survey (DES). If no magnitude
from the DES is available, V magnitude given by JPL - Horizons System - is
used.
Note (3): As provided by JPL, Horizons System.
Note (4): Note that the total number of filters in each row is always less than
or equal to the respective number of positions in column "Npos". This is
because either a magnitude was not found in the DES database for a given
position or the position itself was not found in the DES database.
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 11-Jun-2019