2013TV135, a newly discovered object at the top of the impact risk list


23 October 2013

Soon after having been spotted in the sky on 8 October 2013 from the Crimean Astrophysical Observatory (Ukraine) (on top- Crimean Astrophysical Observatory (Credit: Wikipedia)), asteroid 2013TV135 topped the Risk Page.

Being a relatively large object (500 m in size) it quickly gained the headline news having ramped up the Palermo Scale value for a possible impact in August 2032.

The object has an absolute magnitude of 19.6 and it is currently easily observable. Although the many observations performed worldwide for orbit improvement, the impact probability and Palermo Scale continue to change with no clear pattern.
"We need more data, and also higher quality data with very accurate astrometry; we do not need too many observations, 3-5 observations per night is optimal" suggests Andrea Milani, on behalf of the NEODyS consortium.

Additional information can be extracted from the past history of 2013TV135: computing backwards ephemeris one notices that its brightness peaked at about 16th magnitude in mid-September, well before discovery, when it was observable from the southern hemisphere. Uncertainty analysis reveals that were the object first spotted at that time, its orbit would have been quickly well constrained thus avoiding any further concern.

Thus 2013TV135 is telling us the importance of both, a well coordinated follow-up campaign and the importance of extending the NEO sky surveys to the southern skies. For the time being, stay tuned: the values of the impact probability (IP) and  Palermo Scale (PS) are reported daily in the table below:

 impact date            IP         PS    computation date

 2032/08/26.371  2.02E-5  -1.73    2013/10/16
 2032/08/26.364  2.74E-5  -1.62    2013/10/17
 2032/08/26.355  4.34E-5  -1.41    2013/10/18
 2032/08/26.352  2.65E-4  -0.62    2013/10/19
 2032/08/26.355  1.34E-4  -0.86    2013/10/20
 2032/08/26.354  1.19E-4  -0.88    2013/10/21
 2032/08/26.355  1.22E-4  -0.86    2013/10/22
 2032/08/26.355  1.97E-4  -0.65    2013/10/23
 2032/08/26.357  1.62E-4  -0.74    2013/10/24
 2032/08/26.357  1.02E-4  -0.95    2013/10/25
 2032/08/26.358  7.38E-5  -1.07    2013/10/26
 2032/08/26.358  7.70E-5  -1.06    2013/10/27
 2032/08/26.358  7.43E-5  -1.08    2013/10/28
 2032/08/26.358  9.42E-5  -0.97    2013/10/29
 2032/08/26.358  1.50E-4  -0.77    2013/10/30
 2032/08/26.359  2.31E-4  -0.58    2013/10/31
 2032/08/26.359  2.20E-4  -0.60    2013/11/01
 2032/08/26.359  6.46E-5  -1.14    2013/11/02
 2032/08/26.358  7.58E-6  -2.07    2013/11/03
 2032/08/26.358  5.25E-9  -5.49    2013/11/04
 2032/08/26.358  8.36E-8  -4.03    2013/11/05
 2032/08/26.359  2.79E-7  -3.51    2013/11/06
 2032/08/26.358  1.82E-7  -3.69    2013/11/07

Update: on 8 November 2013 asteroid 2013TV135 has been removed from the Risk Page. The non-zero impact probability spotted by monitoring systems just after its discovery dropped essentially to zero. The bulk of astrometric data collected by astronomers during one month of observations helped to improve our knowledge of its orbit, that eventually turned out to be a safe one.