J/AJ/152/63 NEOWISE reactivation mission: 2nd yr data (Nugent+, 2016)
NEOWISE reactivation mission year two: asteroid diameters and albedos.
Nugent C.R., Mainzer A., Bauer J., Cutri R.M., Kramer E.A., Grav T.,
Masiero J., Sonnett S., Wright E.L.
<Astron. J., 152, 63-63 (2016)>
=2016AJ....152...63N 2016AJ....152...63N (SIMBAD/NED BibCode)
ADC_Keywords: Minor planets ; Photometry, infrared ; Surveys
Keywords: minor planets, asteroids: general - surveys
Abstract:
The Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE)
mission continues to detect, track, and characterize minor planets. We
present diameters and albedos calculated from observations taken
during the second year since the spacecraft was reactivated in late
2013. These include 207 near-Earth asteroids (NEAs) and 8885 other
asteroids. Of the NEAs, 84% NEAs did not have previously measured
diameters and albedos by the NEOWISE mission. Comparison of sizes and
albedos calculated from NEOWISE measurements with those measured by
occultations, spacecraft, and radar-derived shapes shows accuracy
consistent with previous NEOWISE publications. Diameters and albedos
fall within ±∼20% and ±∼40%, 1-sigma, respectively, of those
measured by these alternate techniques. NEOWISE continues to
preferentially discover near-Earth objects which are large (>100m),
and have low albedos.
Description:
We present diameters and albedos of asteroids from the second year of
the Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE)
mission following the reactivation of the spacecraft from hibernation
in late 2013. Diameters and albedos of asteroids from the first year
of the NEOWISE mission following reactivation are given in Nugent et
al. 2015 (Cat. J/ApJ/814/117). NEOWISE is a space-based infrared
telescope that obtains an image of the sky every 11 seconds
simultaneously in two bands, W1 (3.4µm) and W2 (4.6µm). After
successfully completing its prime mission in 2011, the WISE spacecraft
was placed into hibernation for 32 months before being reactivated and
renamed NEOWISE in late 2013. The goals of the NEOWISE mission are to
discover, track, and characterize minor planets. Images and extracted
source lists from all phases of the WISE and NEOWISE missions have
been delivered to the public via the Infrared Science Archive (Cutri
et al. 2012,
http://wise2.ipac.caltech.edu/docs/release/allsky/expsup/sec8_1.html;
Cutri et al. 2015,
http://wise2.ipac.caltech.edu/docs/release/neowise/expsup/), NASA's
designated archive for infrared astronomical data.
This second year of data provides multi-epoch observational data of
uniform quality that can be used to better constrain the sizes,
shapes, rotation state, and thermophysical properties of the 9092
asteroids in the reactivation Year 2 sample. We present preliminary
diameters and albedos calculated from NEOWISE Year 2 Reactivation
mission observations, which spanned 2014 December 13 to 2015 December
13. Diameters and albedos calculated from NEOWISE Year 2 Reactivation
mission observations will be submitted to the Planetary Data System.
NEOWISE discovered 198 Near-Earth Asteroid (NEAs) and comets during
Years 1 and 2 of the Reactivation mission. In addition to observing
175 NEAs that had not had diameters measured previously from NEOWISE
data, the Year 2 Reactivation mission obtained thermal infrared
observations at additional epochs for 32 NEAs. NEOWISE typically
observes asteroids ∼10-12 times over ∼1-1.5days, and requires a
minimum of 5 detections of a discovery candidate for submission to the
Minor Planet Center (MPC).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 49 3498 *NEOWISE magnitudes for the near-Earth asteroids
(NEAs) modeled in this paper
table4.dat 86 251 *Measured diameters and albedos of near-Earth
asteroids observed during NEOWISE year 2 mission
table5.dat 86 10314 *Measured diameters and albedos of non-near-Earth
asteroids observed during NEOWISE year 2 mission
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Note on table3.dat table4.dat table5.dat: Second year (2014 December 13 to 2015
December 13) of the Near-Earth Object Wide-Field Infrared Survey Explorer
(NEOWISE) mission following the reactivation of the spacecraft from hibernation
in late 2013.
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See also:
B/astorb : Orbits of Minor Planets (Bowell+ 2014)
J/ApJ/814/117 : NEOWISE Reactivation mission: 1st yr data (Nugent+, 2015)
J/ApJ/784/110 : NEOWISE observations of near-Earth objects (Mainzer+, 2014)
J/MNRAS/433/2075 : Asteroid families identification (Carruba+, 2013)
J/ApJ/770/7 : WISE/NEOWISE Main Belt asteroids (Masiero+, 2013)
J/ApJ/760/L12 : WISE/NEOWISE NEOs preliminary thermal fits (Mainzer+, 2012)
J/ApJ/759/L8 : WISE/NEOWISE obs. of main belt asteroids (Masiero+, 2012)
J/ApJ/759/49 : Jovian Trojan asteroids with WISE/NEOWISE (Grav+, 2012)
J/ApJ/744/197 : WISE/NEOWISE observations of Hilda asteroids (Grav+, 2012)
J/ApJ/743/156 : NEOWISE obs. of NEOs: preliminary results (Mainzer+, 2011)
J/ApJ/742/40 : Jovian Trojans asteroids with WISE/NEOWISE (Grav+, 2011)
J/ApJ/741/68 : Main Belt asteroids with WISE/NEOWISE. I. (Masiero+, 2011)
http://www.minorplanetcenter.net/iau/ECS/MPCAT-OBS/MPCAT-OBS.html : IAU MPC
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- MPC Asteroid name, in Minor Planet Center (MPC)
packed format
9- 21 F13.7 d MJD Observation time in Modified Julian Date
23 A1 --- f_W1mag [>] Upper limit flag on W1mag (1)
25- 30 F6.3 mag W1mag [11.3/17.3]? WISE 3.4µm (W1) magnitude
32- 36 F5.3 mag e_W1mag [0.01/0.6]? Uncertainty in W1mag
38- 43 F6.3 mag W2mag [8.2/14.8] WISE 4.6µm (W2) magnitude
45- 49 F5.3 mag e_W2mag [0.01/0.29] Uncertainty in W2mag
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Note (1): ">" indicates that the magnitude is a 95% confidence limit;
Cutri et al. 2012wise.rept....1C.
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Byte-by-byte Description of file: table[45].dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Asteroid number or provisional name
12- 18 A7 --- MPC Asteroid name, in Minor Planet Center (MPC)
packed format
20- 24 F5.2 mag HMag [5.4/23.7] Absolute H band magnitude
26- 29 F4.2 --- G [0/0.5] Slope parameter
31- 36 F6.2 km Diam [0.09/451] Asteroid diameter
38- 43 F6.2 km e_Diam [0.01/200.3] Uncertainty in Diam
45- 48 F4.2 --- pV [0.02/0.6] Visible geometrical albedo
50- 53 F4.2 --- e_pV [0/0.3] Uncertainty in pV
55- 58 F4.2 --- eta [0.4/1.8] Beaming parameter, η
60- 63 F4.2 --- e_eta [0/0.8] Uncertainty in η
65- 68 F4.2 --- pIR/pV [0.2/8.7] Ratio infrared to visible geometrical
albedo
70- 73 F4.2 --- e_pIR/pV [0.1/0.6] Uncertainty in pIR/pV
75- 78 F4.2 mag W2amp [0.02/5.3] Amplitude of the WISE 4.6µm (W2)
light curve
80- 82 I3 --- N1 [0/114] Number of WISE 3.4µm (W1) band
observations
84- 86 I3 --- N2 [4/118] Number of WISE 4.6µm (W2) band
observations
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 23-Sep-2016