Accurate Ground-based Near-Earth-Asteroid Astrometry Using Synthetic Tracking

Zhai, Chengxing; Shao, Michael; Saini, Navtej; Sandhu, J. S.; Choi, Phil M.; Owen, W. M.; Werne, Thomas A.; Ely, Todd A.; Lazio, Joseph; Martin-Mur, Tomas J.; Preston, R. A.; Turyshev, Slava G.; Mitchell, Adam; Nazli, Kutay; Cui, Isaac; Mochama, Rachel M.

doi:10.3847/1538-3881/aacb28

Cited by 12 publications

(13 citation statements)

References 10 publications

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“…Although GD can be expressed by a high-order polynomial if there are sufficient Gaia stars in the field of view (FOV), a GD pattern of the CCD camera in a certain time is still desirable. For example, when performing Synthetic Tracking (Zhai et al 2018) for detecting and tracking near-Earth objects (NEO), it is convenient and timesaving to transform the pixel positions to the distortionfree positions by utilizing GD solution, instead of building a high order distortion model (Equations 3 and 4 in Zhai et al 2018).…”

Section: Introductionmentioning

confidence: 99%

Using Gaia DR2 to make a systematic comparison between two geometric distortion solutions

Zheng

Peng

Lin

2021

Monthly Notices of the Royal Astronomical Society

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Gaia Data Release 2 (Gaia DR2) provides high accuracy and precision astrometric parameters (position, parallax, and proper motion) for more than 1 billion sources and is revolutionising astrometry. For a fast-moving target such as an asteroid, with many stars in the field of view that are brighter than the faint limit magnitude of Gaia (21 Gmag), its measurement accuracy and precision can be greatly improved by taking advantage of Gaia reference stars. However, if we want to study the relative motions of cluster members, we could cross-match them in different epochs based on pixel positions. For both types of targets, the determination of optical field-angle distortion or called geometric distortion (GD) in this paper is important for image calibration especially when there are few reference stars to build a high-order plate model. For the former, the GD solution can be derived based on the astrometric catalog’s position, while for the latter, a reference system called ‘master frame’ is constructed from these observations in pixel coordinates, and then the GD solution is derived. But are the two GD solutions in agreement with each other? In this paper, two types of GD solutions, which are derived either from the Gaia DR2 catalog or from the self-constructed master frame, are applied respectively for the observations taken by 1-m telescope at Yunnan Observatory. It is found that two GD solutions enable the precision to achieve a comparable level (∼10 mas) but their GD patterns are different. Synthetic distorted positions are generated for further investigation into the discrepancy between the two GD solutions. We aim to find the correlation and distinction between the two types of GD solutions, and their applicability in high precision astrometry.

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Section: Introductionmentioning

confidence: 99%

Using Gaia DR2 to make a systematic comparison between two geometric distortion solutions

Zheng

Peng

Lin

2021

Monthly Notices of the Royal Astronomical Society

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“…). High dynamic range synthetic tracking (ST) offers a means of avoiding the streak limit in asteroid surveys, and of substantially improving the detectability of small fast-moving bodies (Zhai et al 2018); our analysis suggests that these surveys should try to accommodate as high an incoming velocity as possible, ideally up to hundreds of km s −1 .…”

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confidence: 99%

Interstellar Objects in the Solar System: 1. Isotropic Kinematics from the Gaia Early Data Release 3

Eubanks¹,

Hein²,

Lingam³

et al. 2021

Preprint

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1I/'Oumuamua (or 1I) and 2I/Borisov (or 2I), the first InterStellar Objects (ISOs) discovered passing through the solar system, have opened up entirely new areas of exobody research. Finding additional ISOs and planning missions to intercept or rendezvous with these bodies will greatly benefit from knowledge of their likely orbits and arrival rates. Here, we use the local velocity distribution of stars from the Gaia Early Data Release 3 Catalogue of Nearby Stars and a standard gravitational focusing model to predict the velocity dependent flux of ISOs entering the solar system. With an 1I-type ISO number density of ∼0.1 AU −3 , we predict that a total of ∼6.9 such objects per year should pass within 1 AU of the Sun. There will be a fairly large high-velocity tail to this flux, with half of the incoming ISOs predicted to have a velocity at infinity, v ∞ , > 40 km s −1 . Our model predicts that ∼92% of incoming ISOs will be residents of the galactic thin disk, ∼6% (∼4 per decade) will be from the thick disk, ∼1 per decade will be from the halo and at most ∼3 per century will be unbound objects, ejected from our galaxy or entering the Milky Way from another galaxy. The rate of ISOs with very low v ∞ 1.5 km s −1 is so low in our model that any incoming very low velocity ISOs are likely to be previously lost solar system objects. Finally, we estimate a cometary ISO number density of ∼7 × 10 −5 AU −3 for 2I type ISOs, leading to discovery rates for these objects possibly approaching once per decade with future telescopic surveys.

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“…4 even with the trailing loss when co-adding all the 133 frames to simulate an integration of ∼ 1.5 hours for ZTF tracking the sidereal. Even though this can -9be detected as a streak in the co-added images, for accurate astrometry, the whole datacube is needed to take the advantage of synthetic tracking (Zhai et al 2018). Fig.…”

Section: Resultsmentioning

confidence: 99%

“…It is bright enough to be detected as a streak as shown in the right plot in Figure 4 even with the trailing loss when coadding all the 133 frames to simulate an integration of about 1.5 hr for ZTF tracking the sidereal. Although this can be detected as a streak (blue line) in the co-added images, for accurate astrometry, the whole data cube is needed to take the advantage of ST (Zhai et al 2018). Similarly, Figure 5 displays another main belt asteroid of magnitude of 20.8, whose signals only show in three sub-data cubes because it ran into a masked region due to a bright star.…”

Section: Resultsmentioning

confidence: 99%

Synthetic Tracking Using ZTF Deep Drilling Data Sets

Zhai

Shao

et al. 2020

PASP

Self Cite

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The Zwicky Transit Factory (ZTF) is a powerful time domain survey facility with a large field of view. We apply the synthetic tracking technique to integrate a ZTF's long-dwell dataset, which consists of 133 nominal 30-second exposure frames spanning about 1.5 hours, to search for slowly moving asteroids down to approximately 23rd magnitude. We found more than one thousand objects from searching 40 CCD-quadrant subfields, each of which covers a field size of ∼0.73 deg 2 . While most of the objects are main belt asteroids, there are asteroids belonging to families of Trojan, Hilda, Hungaria, Phocaea, and near-Earth-asteroids. Such an approach is effective and productive. Here we report the data process and results.

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Accurate Ground-based Near-Earth-Asteroid Astrometry Using Synthetic Tracking

Cited by 12 publications

References 10 publications

Using Gaia DR2 to make a systematic comparison between two geometric distortion solutions

Using Gaia DR2 to make a systematic comparison between two geometric distortion solutions

Interstellar Objects in the Solar System: 1. Isotropic Kinematics from the Gaia Early Data Release 3

Synthetic Tracking Using ZTF Deep Drilling Data Sets

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