### Abstract

In the absence of dense photometry for a large population of near-Earth objects (NEOs), the best method of obtaining a shape distribution comes from sparse photometry and partial light curves. We have used 867 partial light curves obtained by Spitzer to determine a shape distribution for subkilometer NEOs. From this data we find a best-fit average elongation of ^{b} _{a} = 0.72 ±0.08. We compare this result with a shape distribution obtained from 1869 NEOs in the same size range observed by Pan-STARRS 1 (PS1) and find the Spitzer-obtained elongation to be in excellent agreement with this PS1 value of ^{b} _{a} = 0.70 ±0.10. These values are also in agreement with literature values for 1 < D < 10 km objects in the main asteroid belt, however, there is a size discrepancy between the two data sets. Using a smaller sample of NEOs in the size range of 1 < D < 5 km from PS1 data, we obtain an average axis ratio of b/a = 0.70 ±0.12. This is more elongated than the shape distribution for main belt objects in the same size regime, although the current uncertainties are sizeable and this should be verified using a larger data set. As future large surveys come online it will be possible to observe smaller main belt asteroids to allow for better comparisons of different subkilometer populations.

Original language | English (US) |
---|---|

Article number | 164 |

Journal | Astronomical Journal |

Volume | 157 |

Issue number | 4 |

DOIs | |

State | Published - Apr 1 2019 |

### Fingerprint

### Keywords

- methods: statistical
- minor planets, asteroids: general
- techniques: photometric

### ASJC Scopus subject areas

- Astronomy and Astrophysics
- Space and Planetary Science

### Cite this

*Astronomical Journal*,

*157*(4), [164]. https://doi.org/10.3847/1538-3881/ab0e6e

**Constraining the Shape Distribution of Near-Earth Objects from Partial Light Curves.** / McNeill, A.; Hora, J. L.; Gustafsson, A.; Trilling, David E; Mommert, M.

Research output: Contribution to journal › Article

*Astronomical Journal*, vol. 157, no. 4, 164. https://doi.org/10.3847/1538-3881/ab0e6e

}

TY - JOUR

T1 - Constraining the Shape Distribution of Near-Earth Objects from Partial Light Curves

AU - McNeill, A.

AU - Hora, J. L.

AU - Gustafsson, A.

AU - Trilling, David E

AU - Mommert, M.

PY - 2019/4/1

Y1 - 2019/4/1

N2 - In the absence of dense photometry for a large population of near-Earth objects (NEOs), the best method of obtaining a shape distribution comes from sparse photometry and partial light curves. We have used 867 partial light curves obtained by Spitzer to determine a shape distribution for subkilometer NEOs. From this data we find a best-fit average elongation of b a = 0.72 ±0.08. We compare this result with a shape distribution obtained from 1869 NEOs in the same size range observed by Pan-STARRS 1 (PS1) and find the Spitzer-obtained elongation to be in excellent agreement with this PS1 value of b a = 0.70 ±0.10. These values are also in agreement with literature values for 1 < D < 10 km objects in the main asteroid belt, however, there is a size discrepancy between the two data sets. Using a smaller sample of NEOs in the size range of 1 < D < 5 km from PS1 data, we obtain an average axis ratio of b/a = 0.70 ±0.12. This is more elongated than the shape distribution for main belt objects in the same size regime, although the current uncertainties are sizeable and this should be verified using a larger data set. As future large surveys come online it will be possible to observe smaller main belt asteroids to allow for better comparisons of different subkilometer populations.

AB - In the absence of dense photometry for a large population of near-Earth objects (NEOs), the best method of obtaining a shape distribution comes from sparse photometry and partial light curves. We have used 867 partial light curves obtained by Spitzer to determine a shape distribution for subkilometer NEOs. From this data we find a best-fit average elongation of b a = 0.72 ±0.08. We compare this result with a shape distribution obtained from 1869 NEOs in the same size range observed by Pan-STARRS 1 (PS1) and find the Spitzer-obtained elongation to be in excellent agreement with this PS1 value of b a = 0.70 ±0.10. These values are also in agreement with literature values for 1 < D < 10 km objects in the main asteroid belt, however, there is a size discrepancy between the two data sets. Using a smaller sample of NEOs in the size range of 1 < D < 5 km from PS1 data, we obtain an average axis ratio of b/a = 0.70 ±0.12. This is more elongated than the shape distribution for main belt objects in the same size regime, although the current uncertainties are sizeable and this should be verified using a larger data set. As future large surveys come online it will be possible to observe smaller main belt asteroids to allow for better comparisons of different subkilometer populations.

KW - methods: statistical

KW - minor planets, asteroids: general

KW - techniques: photometric

UR - http://www.scopus.com/inward/record.url?scp=85067818114&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85067818114&partnerID=8YFLogxK

U2 - 10.3847/1538-3881/ab0e6e

DO - 10.3847/1538-3881/ab0e6e

M3 - Article

VL - 157

JO - Astronomical Journal

JF - Astronomical Journal

SN - 0004-6256

IS - 4

M1 - 164

ER -