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Michael Frühauf

Publications and source records attributed to Michael Frühauf.

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The ESA Meerkat Asteroid Guard: a monitoring service for imminent impactors

We present the Meerkat Asteroid Guard, an imminent impactor warning service developed and maintained by the European Space Agency's Near-Earth Object Coordination Centre (NEOCC). The software uses the method of systematic ranging to perform orbit determination on tracklets in the Near-Earth Object Confirmation Page (NEOCP), which typically have short observational arcs. Fitted orbits are propagated to determine the likelihood of an impact with Earth. In addition, magnitude fitting and Monte Carlo sampling are performed to estimate the object's size, possible impact locations and times, and suggest a best telescope pointing for object follow-up. A set of object scores are produced from computed posterior probabilities across the grid, giving a statistical description of the object's orbital and physical characteristics. The scores are packaged with several informative plots in an email alert, which is sent to Meerkat subscribers in the event of a significant impact probability, close approach, or other scientifically interesting event. The highlights of the five years of Meerkat's operational service are presented, including the successful warnings for all of the past six imminent impactors discovered before impact and several interesting close approaches.

astro-ph.EP

Simulation of Sky Surveys with the Flyeye Telescope

ESA's Flyeye telescope is designed with a very large field of view (FoV) in order to scan the sky for unknown near-Earth Objects (NEOs). For typical exposure times of 40 s, the telescope is able to detect objects with a limiting magnitude up to 21.5. The aim is to observe those NEOs that are going to hit the Earth within a few weeks or days, in advance of impact. In order to estimate the detection rate of NEOs with the Flyeye telescope, a synthetic population of Earth threatening asteroids is created by means of the software NEOPOP. Then, the true anomalies and longitudes of the ascending node of these objects are modified in order to generate about 2500 impactors. In the simulations almost three impacts can be detected per year from NEOs down to 1 m using only one Flyeye telescope. When operating two telescopes simultaneously, one at Monte Mufara and one at La Silla, four detected impacts per year are expected. Nonetheless, it is estimated that about 15.6% of the Earth impactors will be very difficult to be detected using ground-based telescopes due to the fact that they are approaching us from the Sun.

astro-ph.EP

A systematic ranging technique for follow-ups of NEOs detected with the Flyeye telescope

When new objects are detected in the sky, an orbit determination needs to be performed immediately to find out their origin, to determine the probability of an Earth impact and possibly also to estimate the impact region on Earth. ESA's Flyeye telescope is expected to revolutionize the effort of predicting potential asteroid or deep space debris impact hazards due to the expected increase of near-Earth object discoveries. As the observed orbit arc for such an object is very short, classical Gaussian orbit determination cannot be used. We adopt the systematic ranging technique to overcome the lack of information and predict a region of the sky where the body can most likely be found. We also provide a detection probability for follow-up observations and investigate potential follow-up telescopes for the Flyeye telescope.

astro-ph.EP