Shape model and spin-state analysis of PHA contact binary (85990) 1999 JV6 from combined radar and optical observations

A. Rozek; S. C. Lowry; M. C. Nolan; P. A. Taylor; L. A.M. Benner; A. Fitzsimmons; T. J. Zegmott; P. R. Weissman; S. F. Green; B. Rozitis; C. Snodgrass; W. D. Smythe; M. D. Hicks; E. S. Howell; A. K. Virkki; B. Aponte-Hernandez; E. G. Rivera-Valentín; L. A. Rodriguez-Ford; L. F. Zambrano-Marin; M. Brozović; S. P. Naidu; J. D. Giorgini; L. G. Snedeker; J. S. Jao; F. D. Ghigo

doi:10.1051/0004-6361/201936302

Shape model and spin-state analysis of PHA contact binary (85990) 1999 JV6 from combined radar and optical observations

A. Rozek, S. C. Lowry, M. C. Nolan, P. A. Taylor, L. A.M. Benner, A. Fitzsimmons, T. J. Zegmott, P. R. Weissman, S. F. Green, B. Rozitis, C. Snodgrass, W. D. Smythe, M. D. Hicks, E. S. Howell, A. K. Virkki, B. Aponte-Hernandez, E. G. Rivera-Valentín, L. A. Rodriguez-Ford, L. F. Zambrano-Marin, M. BrozovićS. P. Naidu, J. D. Giorgini, L. G. Snedeker, J. S. Jao, F. D. Ghigo

Lunar and Planetary Lab

Research output: Contribution to journal › Article › peer-review

3 Scopus citations

Abstract

Context. The potentially hazardous asteroid (85990) 1999 JV6 has been a target of previously published thermal-infrared observations and optical photometry. It has been identified as a promising candidate for possible Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) effect detection. Aims. The YORP effect is a small thermal-radiation torque considered to be a key factor in spin-state evolution of small Solar System bodies. In order to detect YORP on 1999 JV6 we developed a detailed shape model and analysed the spin-state using both optical and radar observations. Methods. For 1999 JV6, we collected optical photometry between 2007 and 2016. Additionally, we obtained radar echo-power spectra and imaging observations with Arecibo and Goldstone planetary radar facilities in 2015, 2016, and 2017. We combined our data with published optical photometry to develop a robust physical model. Results. We determine that the rotation pole resides at negative latitudes in an area with a 5^◦ radius close to the south ecliptic pole. The refined sidereal rotation period is 6.536787 ± 0.000007 h. The radar images are best reproduced with a bilobed shape model. Both lobes of 1999 JV6 can be represented as oblate ellipsoids with a smaller, more spherical component resting at the end of a larger, more elongated component. While contact binaries appear to be abundant in the near-Earth population, there are only a few published shape models for asteroids in this particular configuration. By combining the radar-derived shape model with optical light curves we determine a constant-period solution that fits all available data well. Using light-curve data alone we determine an upper limit for YORP of 8.5 × 10−⁸ rad day⁻². Conclusions. The bifurcated shape of 1999 JV6 might be a result of two ellipsoidal components gently merging with each other, or a deformation of a rubble pile with a weak-tensile-strength core due to spin-up. The physical model of 1999 JV6 presented here will enable future studies of contact binary asteroid formation and evolution.

Original language	English (US)
Article number	A149
Journal	Astronomy and astrophysics
Volume	631
DOIs	https://doi.org/10.1051/0004-6361/201936302
State	Published - Nov 2019

Keywords

Asteroids: individual: (85990) 1999 JV6
Methods: data analysis
Methods: observational
Minor planets
Radiation mechanisms: thermal
Techniques: photometric
Techniques: radar astronomy

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1051/0004-6361/201936302

Cite this

Rozek, A., Lowry, S. C., Nolan, M. C., Taylor, P. A., Benner, L. A. M., Fitzsimmons, A., Zegmott, T. J., Weissman, P. R., Green, S. F., Rozitis, B., Snodgrass, C., Smythe, W. D., Hicks, M. D., Howell, E. S., Virkki, A. K., Aponte-Hernandez, B., Rivera-Valentín, E. G., Rodriguez-Ford, L. A., Zambrano-Marin, L. F., ... Ghigo, F. D. (2019). Shape model and spin-state analysis of PHA contact binary (85990) 1999 JV6 from combined radar and optical observations. Astronomy and astrophysics, 631, [A149]. https://doi.org/10.1051/0004-6361/201936302

Rozek, A, Lowry, SC, Nolan, MC, Taylor, PA, Benner, LAM, Fitzsimmons, A, Zegmott, TJ, Weissman, PR, Green, SF, Rozitis, B, Snodgrass, C, Smythe, WD, Hicks, MD, Howell, ES, Virkki, AK, Aponte-Hernandez, B, Rivera-Valentín, EG, Rodriguez-Ford, LA, Zambrano-Marin, LF, Brozović, M, Naidu, SP, Giorgini, JD, Snedeker, LG, Jao, JS & Ghigo, FD 2019, 'Shape model and spin-state analysis of PHA contact binary (85990) 1999 JV6 from combined radar and optical observations', Astronomy and astrophysics, vol. 631, A149. https://doi.org/10.1051/0004-6361/201936302

@article{19f69667b45143b59f9d398d4aac884d,

title = "Shape model and spin-state analysis of PHA contact binary (85990) 1999 JV6 from combined radar and optical observations",

abstract = "Context. The potentially hazardous asteroid (85990) 1999 JV6 has been a target of previously published thermal-infrared observations and optical photometry. It has been identified as a promising candidate for possible Yarkovsky-O{\textquoteright}Keefe-Radzievskii-Paddack (YORP) effect detection. Aims. The YORP effect is a small thermal-radiation torque considered to be a key factor in spin-state evolution of small Solar System bodies. In order to detect YORP on 1999 JV6 we developed a detailed shape model and analysed the spin-state using both optical and radar observations. Methods. For 1999 JV6, we collected optical photometry between 2007 and 2016. Additionally, we obtained radar echo-power spectra and imaging observations with Arecibo and Goldstone planetary radar facilities in 2015, 2016, and 2017. We combined our data with published optical photometry to develop a robust physical model. Results. We determine that the rotation pole resides at negative latitudes in an area with a 5◦ radius close to the south ecliptic pole. The refined sidereal rotation period is 6.536787 ± 0.000007 h. The radar images are best reproduced with a bilobed shape model. Both lobes of 1999 JV6 can be represented as oblate ellipsoids with a smaller, more spherical component resting at the end of a larger, more elongated component. While contact binaries appear to be abundant in the near-Earth population, there are only a few published shape models for asteroids in this particular configuration. By combining the radar-derived shape model with optical light curves we determine a constant-period solution that fits all available data well. Using light-curve data alone we determine an upper limit for YORP of 8.5 × 10−8 rad day−2. Conclusions. The bifurcated shape of 1999 JV6 might be a result of two ellipsoidal components gently merging with each other, or a deformation of a rubble pile with a weak-tensile-strength core due to spin-up. The physical model of 1999 JV6 presented here will enable future studies of contact binary asteroid formation and evolution.",

keywords = "Asteroids: individual: (85990) 1999 JV6, Methods: data analysis, Methods: observational, Minor planets, Radiation mechanisms: thermal, Techniques: photometric, Techniques: radar astronomy",

author = "A. Rozek and Lowry, {S. C.} and Nolan, {M. C.} and Taylor, {P. A.} and Benner, {L. A.M.} and A. Fitzsimmons and Zegmott, {T. J.} and Weissman, {P. R.} and Green, {S. F.} and B. Rozitis and C. Snodgrass and Smythe, {W. D.} and Hicks, {M. D.} and Howell, {E. S.} and Virkki, {A. K.} and B. Aponte-Hernandez and Rivera-Valent{\'i}n, {E. G.} and Rodriguez-Ford, {L. A.} and Zambrano-Marin, {L. F.} and M. Brozovi{\'c} and Naidu, {S. P.} and Giorgini, {J. D.} and Snedeker, {L. G.} and Jao, {J. S.} and Ghigo, {F. D.}",

note = "Funding Information: Acknowledgements. We thank the referee, Chris Magri, for his comments which helped to improve the manuscript. A.R., S.C.L., S.F.G., C.S., and A.F. acknowledge support from the UK Science and Technology Facilities Council. A.R. and S.C.L. acknowledge support from the South East Physics Network (SEPnet). A.R. acknowledges support from the Royal Astronomical Society (RAS) in the form of a travel grant. B.R. acknowledges support from the RAS in the form of a research fellowship. P.W. acknowledges the U.S. Social Security Administration for financial support. We thank all the staff at the observatories involved in this study for their support, especially James Frederick (Pasadena City College) and Mark Shiffer (Los Angeles Valley College) at the TMO. The Arecibo Observatory is a facility of the National Science Foundation that has been operated under a cooperative agreement by University of Central Florida, Yang Enterprises, Inc., and Universidad Ana G. M{\'e}ndez since April 2018. During the observations in 2015, 2016 and 2017, Arecibo Observatory was operated by SRI International under a cooperative agreement with Universidad Metropolitana, and the Universities Space Research Association (USRA). The radar observations were fully funded by the National Aeronautics and Space Administration through the Near-Earth Object Observations program through grants No. NNX12AF24G and NNX13AQ46G awarded to USRA. The Arecibo Planetary Radar observations were collected under programmes R2959, R3035, and R3036. The work at the Jet Propulsion Laboratory, California Institute of Technology was performed under contract with the National Aeronautics and Space Administration (NASA). This material is based in part on work supported by NASA under the Science Mission Directorate Research and Analysis Programs. Based in part on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 185.C-1033(R). Based in part on observations collected at the Isaac Newton Telescope in Spain (under programmes I/2007A/4 and I/2016A/10) and at the Table Mountain Observatory in USA. The Image Reduction and Analysis Facility software was used for data reduction. The asteroid ephemerides were generated using JPL{\textquoteright}s Horizons service. This research has made use of data and services provided by the International Astronomical Union{\textquoteright}s Minor Planet Center. This work uses data obtained from the ALCDEF database, which is supported by funding from NASA grant 80NSSC18K0851. We thank Chris Magri for providing the SHAPE software package. Publisher Copyright: {\textcopyright} ESO 2019",

year = "2019",

month = nov,

doi = "10.1051/0004-6361/201936302",

language = "English (US)",

volume = "631",

journal = "Astronomy and Astrophysics",

issn = "0004-6361",

publisher = "EDP Sciences",

}

TY - JOUR

T1 - Shape model and spin-state analysis of PHA contact binary (85990) 1999 JV6 from combined radar and optical observations

AU - Rozek, A.

AU - Lowry, S. C.

AU - Nolan, M. C.

AU - Taylor, P. A.

AU - Benner, L. A.M.

AU - Fitzsimmons, A.

AU - Zegmott, T. J.

AU - Weissman, P. R.

AU - Green, S. F.

AU - Rozitis, B.

AU - Snodgrass, C.

AU - Smythe, W. D.

AU - Hicks, M. D.

AU - Howell, E. S.

AU - Virkki, A. K.

AU - Aponte-Hernandez, B.

AU - Rivera-Valentín, E. G.

AU - Rodriguez-Ford, L. A.

AU - Zambrano-Marin, L. F.

AU - Brozović, M.

AU - Naidu, S. P.

AU - Giorgini, J. D.

AU - Snedeker, L. G.

AU - Jao, J. S.

AU - Ghigo, F. D.

N1 - Funding Information: Acknowledgements. We thank the referee, Chris Magri, for his comments which helped to improve the manuscript. A.R., S.C.L., S.F.G., C.S., and A.F. acknowledge support from the UK Science and Technology Facilities Council. A.R. and S.C.L. acknowledge support from the South East Physics Network (SEPnet). A.R. acknowledges support from the Royal Astronomical Society (RAS) in the form of a travel grant. B.R. acknowledges support from the RAS in the form of a research fellowship. P.W. acknowledges the U.S. Social Security Administration for financial support. We thank all the staff at the observatories involved in this study for their support, especially James Frederick (Pasadena City College) and Mark Shiffer (Los Angeles Valley College) at the TMO. The Arecibo Observatory is a facility of the National Science Foundation that has been operated under a cooperative agreement by University of Central Florida, Yang Enterprises, Inc., and Universidad Ana G. Méndez since April 2018. During the observations in 2015, 2016 and 2017, Arecibo Observatory was operated by SRI International under a cooperative agreement with Universidad Metropolitana, and the Universities Space Research Association (USRA). The radar observations were fully funded by the National Aeronautics and Space Administration through the Near-Earth Object Observations program through grants No. NNX12AF24G and NNX13AQ46G awarded to USRA. The Arecibo Planetary Radar observations were collected under programmes R2959, R3035, and R3036. The work at the Jet Propulsion Laboratory, California Institute of Technology was performed under contract with the National Aeronautics and Space Administration (NASA). This material is based in part on work supported by NASA under the Science Mission Directorate Research and Analysis Programs. Based in part on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 185.C-1033(R). Based in part on observations collected at the Isaac Newton Telescope in Spain (under programmes I/2007A/4 and I/2016A/10) and at the Table Mountain Observatory in USA. The Image Reduction and Analysis Facility software was used for data reduction. The asteroid ephemerides were generated using JPL’s Horizons service. This research has made use of data and services provided by the International Astronomical Union’s Minor Planet Center. This work uses data obtained from the ALCDEF database, which is supported by funding from NASA grant 80NSSC18K0851. We thank Chris Magri for providing the SHAPE software package. Publisher Copyright: © ESO 2019

PY - 2019/11

Y1 - 2019/11

N2 - Context. The potentially hazardous asteroid (85990) 1999 JV6 has been a target of previously published thermal-infrared observations and optical photometry. It has been identified as a promising candidate for possible Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) effect detection. Aims. The YORP effect is a small thermal-radiation torque considered to be a key factor in spin-state evolution of small Solar System bodies. In order to detect YORP on 1999 JV6 we developed a detailed shape model and analysed the spin-state using both optical and radar observations. Methods. For 1999 JV6, we collected optical photometry between 2007 and 2016. Additionally, we obtained radar echo-power spectra and imaging observations with Arecibo and Goldstone planetary radar facilities in 2015, 2016, and 2017. We combined our data with published optical photometry to develop a robust physical model. Results. We determine that the rotation pole resides at negative latitudes in an area with a 5◦ radius close to the south ecliptic pole. The refined sidereal rotation period is 6.536787 ± 0.000007 h. The radar images are best reproduced with a bilobed shape model. Both lobes of 1999 JV6 can be represented as oblate ellipsoids with a smaller, more spherical component resting at the end of a larger, more elongated component. While contact binaries appear to be abundant in the near-Earth population, there are only a few published shape models for asteroids in this particular configuration. By combining the radar-derived shape model with optical light curves we determine a constant-period solution that fits all available data well. Using light-curve data alone we determine an upper limit for YORP of 8.5 × 10−8 rad day−2. Conclusions. The bifurcated shape of 1999 JV6 might be a result of two ellipsoidal components gently merging with each other, or a deformation of a rubble pile with a weak-tensile-strength core due to spin-up. The physical model of 1999 JV6 presented here will enable future studies of contact binary asteroid formation and evolution.

AB - Context. The potentially hazardous asteroid (85990) 1999 JV6 has been a target of previously published thermal-infrared observations and optical photometry. It has been identified as a promising candidate for possible Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) effect detection. Aims. The YORP effect is a small thermal-radiation torque considered to be a key factor in spin-state evolution of small Solar System bodies. In order to detect YORP on 1999 JV6 we developed a detailed shape model and analysed the spin-state using both optical and radar observations. Methods. For 1999 JV6, we collected optical photometry between 2007 and 2016. Additionally, we obtained radar echo-power spectra and imaging observations with Arecibo and Goldstone planetary radar facilities in 2015, 2016, and 2017. We combined our data with published optical photometry to develop a robust physical model. Results. We determine that the rotation pole resides at negative latitudes in an area with a 5◦ radius close to the south ecliptic pole. The refined sidereal rotation period is 6.536787 ± 0.000007 h. The radar images are best reproduced with a bilobed shape model. Both lobes of 1999 JV6 can be represented as oblate ellipsoids with a smaller, more spherical component resting at the end of a larger, more elongated component. While contact binaries appear to be abundant in the near-Earth population, there are only a few published shape models for asteroids in this particular configuration. By combining the radar-derived shape model with optical light curves we determine a constant-period solution that fits all available data well. Using light-curve data alone we determine an upper limit for YORP of 8.5 × 10−8 rad day−2. Conclusions. The bifurcated shape of 1999 JV6 might be a result of two ellipsoidal components gently merging with each other, or a deformation of a rubble pile with a weak-tensile-strength core due to spin-up. The physical model of 1999 JV6 presented here will enable future studies of contact binary asteroid formation and evolution.

KW - Asteroids: individual: (85990) 1999 JV6

KW - Methods: data analysis

KW - Methods: observational

KW - Minor planets

KW - Radiation mechanisms: thermal

KW - Techniques: photometric

KW - Techniques: radar astronomy

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U2 - 10.1051/0004-6361/201936302

DO - 10.1051/0004-6361/201936302

M3 - Article

AN - SCOPUS:85079034320

VL - 631

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

M1 - A149

ER -

Shape model and spin-state analysis of PHA contact binary (85990) 1999 JV6 from combined radar and optical observations

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PHA contact-binary (85990) 1999 JV6 light curves

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Shape model and spin-state analysis of PHA contact binary (85990) 1999 JV6 from combined radar and optical observations

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ASJC Scopus subject areas

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PHA contact-binary (85990) 1999 JV6 light curves

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