Observational investigation of the 2013 near-Earth encounter by asteroid (367943) Duende

被引：3

作者：

Moskovitz, Nicholas A. ^{[1
]}

Benson, Conor James ^{[2
]}

Scheeres, Daniel ^{[2
]}

Endicott, Thomas ^{[3
]}

Polishook, David ^{[4
]}

Binzel, Richard ^{[5
]}

DeMeo, Francesca ^{[5
]}

Ryan, William ^{[6
]}

Ryan, Eileen ^{[6
]}

Willman, Mark ^{[7
]}

Hergenrother, Carl ^{[8
]}

Verveer, Arie ^{[9
]}

Lister, Tim ^{[10
]}

Birtwhistle, Peter ^{[11
]}

Sickafoose, Amanda ^{[5
,12
,15
]}

Nagayama, Takahiro ^{[13
]}

Gilmore, Alan ^{[14
]}

Kilmartin, Pam ^{[14
]}

Benecchi, Susan ^{[15
]}

Sheppard, Scott ^{[16
]}

Marchis, Franck ^{[17
]}

Augusteijn, Thomas ^{[18
]}

Smirnova, Olesja ^{[18
]}

机构：

[1] Lowell Observ, 1400 West Mars Hill Rd, Flagstaff, AZ 86001 USA

[2] Univ Colorado, Boulder, CO 80305 USA

[3] Univ Massachusetts, Boston, MA 02125 USA

[4] Weizmann Inst Sci, 234 Herzl St, IL-7610001 Rehovot, Israel

[5] MIT, EAPS, 77 Massachusetts Ave, Cambridge, MA 02139 USA

[6] New Mexico Inst Min & Technol, Socorro, NM 87801 USA

[7] Univ Hawaii, Inst Astron, Hilo, HI 96720 USA

[8] Univ Arizona, LPL, Tucson, AZ 85721 USA

[9] Perth Observ, Bickley, WA 6076, Australia

[10] Las Cumbres Observ Global Telescope Network, Goleta, CA 93117 USA

[11] Great Shefford Observ, Great Shefford, Berks, England

[12] South African Astron Observ, Cape Town, South Africa

[13] Kagoshima Univ, Kagoshima, Japan

[14] Univ Canterbury, Mt John Univ Observ, Lake Tekapo, New Zealand

[15] Planetary Sci Inst, 1700 E Ft Lowell Rd, Tucson, AZ 85719 USA

[16] Carnegie Inst Sci, Dept Terr Magnetism, 5241 Broad Branch Rd NW, Washington, DC 20015 USA

[17] SETI Inst, Carl Sagan Ctr, 189 Bernardo Ave, Mountain View, CA 94043 USA

[18] Nordic Opt Telescope, La Palma, Spain

来源：

ICARUS | 2020年 / 340卷

基金：

美国国家科学基金会;

关键词：

Asteroids; dynamics; rotation; composition; Near-Earth objects; PRINCIPAL-AXIS ROTATION; SPIN-STATE; LIGHTCURVES; TELESCOPE; CATALOG; COLORS; SIZE;

D O I：

10.1016/j.icarus.2019.113519

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

On 15 February 2013, the asteroid 367943 Duende (2012 DA14) experienced a near-Earth encounter at an altitude of 27,700 km or 4.2 Earth radii. We present here the results of an extensive, multi-observatory campaign designed to probe for spectral and/or rotational changes to Duende due to gravitational interactions with the Earth during the flyby. Our spectral data reveal no changes within systematic uncertainties. Post-flyby lightcurve photometry places strong constraints on the rotation state of Duende, showing that it is in non-principal axis rotation with fundamental periods of P-1 = 8.71 +/- 0.03 and P-2 = 23.7 +/- 0.2 h. Multiple lightcurve analysis techniques, coupled with theoretical considerations and delay-Doppler radar imaging, allow us to assign these periods to specific rotational axes of the body. In particular we suggest that Duende is now in a non-principal, short axis mode rotation state with a precessional period equal to P-1 and oscillation about the symmetry axis at a rate equal to P-2. Temporal and signal-to-noise limitations inherent to the pre-flyby photometric dataset make it difficult to definitively diagnose whether these periods represent a change imparted due to gravitational torques during the flyby. However, based on multiple analysis techniques and a number of plausibility arguments, we suggest that Duende experienced a rotational change during the planetary encounter with an increase in its precessional rotation period. Our preferred interpretation of the available data is that the precession rate increased from 8.4 h prior to the flyby to 8.7 h afterwards. A companion paper by Benson et al. (2019) provides a more detailed dynamical analysis of this event and compares the data to synthetic lightcurves computed from a simple shape model of Duende. The interpretation and results presented in these two works are consistent with one another. The ultimate outcome of this campaign suggests that the analytic tools we employed are sufficient to extract detailed information about solid-body rotation states given data of high enough quality and temporal sampling. As current and future discovery surveys find more near-Earth asteroids, the opportunities to monitor for physical changes during planetary encounters will increase.

引用

页数：14

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