J/AJ/154/168 NEOWISE: thermal model fits for NEOs and MBAs (Masiero+, 2017)
NEOWISE reactivation mission year three: asteroid diameters and albedos.
Masiero J.R., Nugent C., Mainzer A.K., Wright E.L., Bauer J.M., Cutri R.M.,
Grav T., Kramer E., Sonnett S.
<Astron. J., 154, 168 (2017)>
=2017AJ....154..168M 2017AJ....154..168M (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Minor planets ; Photometry, infrared ; Morphology ;
Surveys
Keywords: minor planets, asteroids: general
Abstract:
The Near-Earth ObjectWide-field Infrared Survey Explorer (NEOWISE)
reactivation mission has completed its third year of surveying the sky
in the thermal infrared for near-Earth asteroids and comets. NEOWISE
collects simultaneous observations at 3.4 and 4.6 µm of solar system
objects passing through its field of regard. These data allow for the
determination of total thermal emission from bodies in the inner solar
system, and thus the sizes of these objects. In this paper, we present
thermal model fits of asteroid diameters for 170 NEOs and 6110 Main Belt
asteroids (MBAs) detected during the third year of the survey, as well
as the associated optical geometric albedos. We compare our results
with previous thermal model results from NEOWISE for overlapping
sample sets, as well as diameters determined through other independent
methods, and find that our diameter measurements for NEOs agree to
within 26% (1σ) of previously measured values. Diameters for the
MBAs are within 17% (1σ). This brings the total number of unique
near-Earth objects characterized by the NEOWISE survey to 541, surpassing
the number observed during the fully cryogenic mission in 2010.
Description:
The NEOWISE telescope uses beamsplitters and co-aligned detectors to
simultaneously image the same 47'x47' area of sky onto two focal plane
detectors with sensitivities centered at 3.4 and 4.6 µm. Each detector
records the incident flux for 7.7 s exposures, followed by an ∼2 s slew
of the scan mirror that keeps the image stationary on the detectors during
exposures. Exposures are separated by 11 s, and have an ∼10% overlap in
the scan direction. The nominal survey pattern results in most detections
of moving objects being spaced ∼3 hr apart over an ∼30 hr period.
We extracted all detections from NEOWISE (observatory code C51) recorded
in the MPC's Observations Catalog
(http://minorplanetcenter.net/iau/ECS/MPCAT-OBS/MPCAT-OBS.html) with
observation dates between 2015 December 13 00:00 UT and 2016 December 12
23:59:59 UT.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 74 202 Thermal model fits for NEOs in the third year
of the NEOWISE survey
table2.dat 74 6877 Thermal model fits for MBAs in the third year
of the NEOWISE survey
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See also:
J/ApJ/741/68 : Main Belt asteroids with WISE/NEOWISE. I. (Masiero+, 2011)
J/ApJ/742/40 : Jovian Trojans asteroids with WISE/NEOWISE (Grav+, 2011)
J/ApJ/743/156 : NEOWISE observations of NEOs: preliminary results
(Mainzer+, 2011)
J/ApJ/744/197 : WISE/NEOWISE observations of Hilda asteroids (Grav+, 2012)
J/ApJ/759/L8 : WISE/NEOWISE observations of main belt asteroids
(Masiero+, 2012)
J/ApJ/760/L12 : WISE/NEOWISE NEOs preliminary thermal fits (Mainzer+, 2012)
J/ApJ/770/7 : WISE/NEOWISE Main Belt asteroids: family members
(Masiero+, 2013)
J/ApJ/791/121 : NIR albedos of main-belt asteroids (Masiero+, 2014)
J/ApJ/792/30 : NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)
J/ApJ/814/117 : NEOWISE Reactivation mission: 1st yr data (Nugent+, 2015)
J/AJ/152/63 : NEOWISE reactivation mission: 2nd yr data (Nugent+, 2016)
http://minorplanetcenter.net/ : IAU Minor Planet Center home page
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Object identifier (1)
9- 13 F5.2 mag HMag [6.74/25.2] Absolute visual magnitude (2)
15- 19 F5.2 --- G [-0.27/0.82] Photometric slope parameter
21- 27 F7.3 km Diam [0.086/216.061] Diameter
29- 34 F6.3 km e_Diam [0.002/72.296] Uncertainty in Diam
36- 41 F6.3 [-] logpV [-1.964/-0.112] Log of the visible albedo
43- 47 F5.3 [-] e_logpV [0.023/0.603] Uncertainty in logpV
49- 53 F5.3 --- eta [0.3/2.724] Beaming parameter η
55- 59 F5.3 --- e_eta [0/0.605] Uncertainty in eta
61- 62 I2 --- NW1 [0/92] Number of unsaturated W1 band observations
(3)
64- 66 I3 --- NW2 [4/104] Number of unsaturated W2 band
observations (3)
68- 72 F5.2 deg Phase [16.32/84.34] Phase angle
74 A1 --- Fitted [0/1] Fitted beaming? (4)
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Note (1): In packed Minor Planet Center (MPC) format. Objects listed multiple
times were observed at multiple epochs and fit separately.
Note (2): 1 AU away and 1 AU from Sun at zero phase angle.
Note (3): Used for fitting.
Note (4): Fitted beaming flag as follows:
1 = Beaming was a fitted parameter;
0 = In case of an assumed value.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 12-Jul-2018