NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos

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 and 8,885 other asteroids. $84\%$ of the near-Earth asteroids 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 $ \pm \sim20\%$ and $\pm\sim40\%$, 1-sigma, respectively, of those measured by these alternate techniques. NEOWISE continues to preferentially discover near-Earth objects which are large ($>100$ m), and have low albedos.

[1]  J. Masiero,et al.  PRELIMINARY ANALYSIS OF WISE/NEOWISE 3-BAND CRYOGENIC AND POST-CRYOGENIC OBSERVATIONS OF MAIN BELT ASTEROIDS , 2012, 1209.5794.

[2]  Petr Pravec,et al.  The asteroid lightcurve database , 2009 .

[3]  Giovanni F. Gronchi,et al.  An Algebraic Method to Compute the Critical Points of the Distance Function Between Two Keplerian Orbits , 2005 .

[4]  C. Broeck,et al.  SEARCH FOR GRAVITATIONAL WAVES ASSOCIATED WITH GAMMA-RAY BURSTS DURING LIGO SCIENCE RUN 6 AND VIRGO SCIENCE RUNS 2 AND 3 , 2012, 1205.2216.

[5]  W. Bottke,et al.  Introducing the Eulalia and new Polana asteroid families: Re-assessing primitive asteroid families in the inner Main Belt , 2013, 1305.2821.

[6]  T. Grav,et al.  THERMAL MODEL CALIBRATION FOR MINOR PLANETS OBSERVED WITH WIDE-FIELD INFRARED SURVEY EXPLORER/NEOWISE , 2011 .

[7]  E. F. Tedesco,et al.  Asteroid albedos deduced from stellar occultations , 2006 .

[8]  T. Grav,et al.  INITIAL PERFORMANCE OF THE NEOWISE REACTIVATION MISSION , 2014, 1406.6025.

[9]  Clark R. Chapman,et al.  The Shape of Gaspra , 1994 .

[10]  E. L. Wright,et al.  NEOWISE OBSERVATIONS OF NEAR-EARTH OBJECTS: PRELIMINARY RESULTS , 2011, 1109.6400.

[11]  Amy K. Mainzer,et al.  NEOWISE: OBSERVATIONS OF THE IRREGULAR SATELLITES OF JUPITER AND SATURN , 2015, 1505.07820.

[12]  M. Kaasalainen,et al.  Combining asteroid models derived by lightcurve inversion with asteroidal occultation silhouettes , 2011, 1104.4227.

[13]  T. Grav,et al.  THE POPULATION OF TINY NEAR-EARTH OBJECTS OBSERVED BY NEOWISE , 2013, 1310.2980.

[14]  T. Grav,et al.  WISE/NEOWISE OBSERVATIONS OF THE HILDA POPULATION: PRELIMINARY RESULTS , 2011, 1110.0283.

[15]  T. Grav,et al.  PHYSICAL PARAMETERS OF ASTEROIDS ESTIMATED FROM THE WISE 3-BAND DATA AND NEOWISE POST-CRYOGENIC SURVEY , 2012, 1210.0502.

[16]  S. Ostro,et al.  A radar survey of main-belt asteroids: Arecibo observations of 55 objects during 1999–2003 , 2007 .

[17]  E. L. Wright,et al.  PRELIMINARY RESULTS FROM NEOWISE: AN ENHANCEMENT TO THE WIDE-FIELD INFRARED SURVEY EXPLORER FOR SOLAR SYSTEM SCIENCE , 2011, 1102.1996.

[18]  T. Grav,et al.  NEOWISE REACTIVATION MISSION YEAR ONE: PRELIMINARY ASTEROID DIAMETERS AND ALBEDOS , 2015, 1509.02522.

[19]  T. B. Spahr,et al.  MAIN BELT ASTEROIDS WITH WISE/NEOWISE. I. PRELIMINARY ALBEDOS AND DIAMETERS , 2011, 1109.4096.

[20]  M. Malin,et al.  Mathilde: Size, Shape, and Geology , 1999 .

[21]  Karen J. Meech,et al.  The NEOWISE-Discovered Comet Population and the CO+CO2 production rates , 2015 .

[22]  Richard P. Binzel,et al.  Phase II of the Small Main-Belt Asteroid Spectroscopic Survey: A Feature-Based Taxonomy , 2002 .

[23]  D. Trilling,et al.  EXPLORENEOs. I. DESCRIPTION AND FIRST RESULTS FROM THE WARM SPITZER NEAR-EARTH OBJECT SURVEY , 2010 .

[24]  T. Grav,et al.  CHARACTERIZING SUBPOPULATIONS WITHIN THE NEAR-EARTH OBJECTS WITH NEOWISE: PRELIMINARY RESULTS , 2012, 1205.3568.

[25]  J. Masiero,et al.  ASTEROID FAMILY IDENTIFICATION USING THE HIERARCHICAL CLUSTERING METHOD AND WISE/NEOWISE PHYSICAL PROPERTIES , 2013, 1305.1607.

[26]  Martin G. Cohen,et al.  THE WIDE-FIELD INFRARED SURVEY EXPLORER (WISE): MISSION DESCRIPTION AND INITIAL ON-ORBIT PERFORMANCE , 2010, 1008.0031.

[27]  Alberto Cellino,et al.  Asteroid families classification: Exploiting very large datasets , 2013, 1312.7702.

[28]  Alan W. Harris,et al.  A Thermal Model for Near-Earth Asteroids , 1998 .

[29]  J.Lee,et al.  THE DARK ENERGY CAMERA , 2004, The Dark Energy Survey.

[30]  M. Nolan,et al.  RADAR IMAGING AND CHARACTERIZATION OF THE BINARY NEAR-EARTH ASTEROID (185851) 2000 DP107 , 2015, 1503.01743.

[31]  R. S. Hudson,et al.  Shape of Asteroid 4769 Castalia (1989 PB) from Inversion of Radar Images , 1994, Science.

[32]  E. Wright,et al.  WISE/NEOWISE PRELIMINARY ANALYSIS AND HIGHLIGHTS OF THE 67P/CHURYUMOV-GERASIMENKO NEAR NUCLEUS ENVIRONS , 2012, 1209.2363.

[33]  B. Zellner.  Asteroid taxonomy and the distribution of the compositional types , 1979 .

[34]  Amy K. Mainzer,et al.  WISE/NEOWISE OBSERVATIONS OF THE JOVIAN TROJAN POPULATION: TAXONOMY , 2012, 1209.1549.

[35]  E. Wright,et al.  OBSERVED ASTEROID SURFACE AREA IN THE THERMAL INFRARED , 2016, 1612.01614.

[36]  A. Harris,et al.  Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations , 2012 .

[37]  J. Masiero,et al.  MAIN-BELT ASTEROIDS WITH WISE/NEOWISE: NEAR-INFRARED ALBEDOS , 2014, 1406.6645.

[38]  Karen J. Meech,et al.  WISE/NEOWISE OBSERVATIONS OF COMET 103P/HARTLEY 2 , 2011, 1107.2637.

[39]  Lance A. M. Benner,et al.  A radar survey of M- and X-class asteroids II. Summary and synthesis , 2010 .

[40]  I. Hook,et al.  The Gemini–North Multi‐Object Spectrograph: Performance in Imaging, Long‐Slit, and Multi‐Object Spectroscopic Modes , 2004 .

[41]  W. Burgett,et al.  Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 – Preliminary results , 2015, 1506.00762.

[42]  R. Wijnands,et al.  TWO NEW BURSTING NEUTRON STAR LOW-MASS X-RAY BINARIES: SWIFT J185003.2–005627 AND SWIFT J1922.7–1716 , 2012, 1208.2966.

[43]  T. Grav,et al.  WISE/NEOWISE OBSERVATIONS OF THE JOVIAN TROJANS: PRELIMINARY RESULTS , 2011, 1110.0280.

[44]  J. Masiero,et al.  THE EUPHROSYNE FAMILY’S CONTRIBUTION TO THE LOW ALBEDO NEAR-EARTH ASTEROIDS , 2015, 1507.07887.

[45]  J. Blum,et al.  Thermophysical properties of near-Earth asteroid (341843) 2008 EV5 from WISE data , 2013, 1310.6715.

[46]  Stephan D. Price,et al.  The Supplemental IRAS Minor Planet Survey , 2002 .

[47]  I. Shapiro,et al.  Mainbelt Asteroids: Results of Arecibo and Goldstone Radar Observations of 37 Objects during 1980-1995 , 1998 .

[48]  E. Wright,et al.  THERMAL MODEL CALIBRATION FOR MINOR PLANETS OBSERVED WITH WISE/NEOWISE: COMPARISON WITH INFRARED ASTRONOMICAL SATELLITE , 2011, 1106.5734.

[49]  J. Licandro,et al.  Near-Earth asteroid (3200) Phaethon. Characterization of its orbit, spin state, and thermophysical parameters , 2016, 1605.05205.

[50]  J. Spencer.  A rough-surface thermophysical model for airless planets , 1990 .

[51]  Edward L. Wright,et al.  Characterizing asteroids multiply-observed at infrared wavelengths , 2015, 1506.04751.

[52]  E. Tedesco,et al.  Compositional Structure of the Asteroid Belt , 1982, Science.

[53]  Karen J. Meech,et al.  CENTAURS AND SCATTERED DISK OBJECTS IN THE THERMAL INFRARED: ANALYSIS OF WISE/NEOWISE OBSERVATIONS , 2013, 1306.1862.

[54]  D. Souami,et al.  A multidomain approach to asteroid families’ identification , 2013, 1305.4847.

[55]  Karen J. Meech,et al.  WISE/NEOWISE observations of Active Bodies in the Main Belt , 2012 .