The Pan-STARRS search for Near Earth Asteroids - Present Status and Future Plans Richard Wainscoat Peter Vereš, Bryce Bolin, Marco Micheli, Larry Denneau, Robert Jedicke, Serge Chastel University of Hawaii, Institute for Astronomy The Pan-STARRS telescopes Pan-STARRS1 is a 1.8-meter diameter telescope at Haleakala observatory in Maui (PS1) A second telescope (PS2) is being built adjacent to PS1 PS1 has the largest digital camera in the world 60 CCDs, each with 4800x4800 pixels, arranged in an 8x8 grid of 600x600 pixels Gigapixel camera 1,382,400,000 pixels 7 square degree field-of-view Read time 12 sec Moon Some CCDs are cosmetically poor 70% fill factor Pan-STARRS1 mission The observations that Pan-STARRS1 is obtaining are designed for many different scientific goals, including the solar system, brown dwarfs, Galactic structure, supernovae and other transients, and cosmology Nearly all observations that Pan-STARRS 1 obtains are executed in a manner that allows them to be searched for Near Earth Objects NASA is funding the NEO search with PS1 Astrometry from PS1 is excellent, and in most cases is better than 0.15 arcsec 3pi survey Entire sky north of –30 surveyed every year 2,500 square degrees observed every month using 56% of the observing time Two pairs in each of g, r, and i (12 observations total) Each pair separated by approximately 20 minutes The entire area is observed at least once as a quad (four observations each spaced 20 minutes apart) 239 NEOs discovered to date including 24 PHAs webviz 10/16/12 11:01 AM MDRM Viewer 136 | 137 | 138 | 139 | 140 | 141 | 142 | 143 | 144 | 145 | 146 | 147 | 148 | 149 | 150 | 151 | 152 | 153 | 154 | 155 | 156 157 158 159 October 3pi fields Show: (Examples: "3pi", "3pi r 1") Previous night Chunk Name 157.3PI.00.BNE1.J.g 157.3PI.00.BNE1.J.i 157.3PI.00.BNE1.J.r 157.3PI.00.BNE1.K.g 157.3PI.00.BNE1.K.i 157.3PI.00.BNE1.K.r 157.3PI.00.BNE2.J.g 157.3PI.00.BNE2.J.i 157.3PI.00.BNE2.J.r 157.3PI.00.BNE2.K.g 157.3PI.00.BNE2.K.i 157.3PI.00.BNE2.K.r 157.3PI.00.BNE3.J.g 157.3PI.00.BNE3.J.i 157.3PI.00.BNE3.J.r 157.3PI.00.BNE3.K.g 157.3PI.00.BNE3.K.i 157.3PI.00.BNE3.K.r 157.3PI.00.BNO1.J.g 157.3PI.00.BNO1.J.i 157.3PI.00.BNO1.J.r 157.3PI.00.BNO1.K.g 157.3PI.00.BNO1.K.i 157.3PI.00.BNO1.K.r 157.3PI.00.BNO2.J.g 157.3PI.00.BNO2.J.i 157.3PI.00.BNO2.J.r 157.3PI.00.BNO2.K.g 157.3PI.00.BNO2.K.i 157.3PI.00.BNO2.K.r 157.3PI.00.BNO3.J.g 157.3PI.00.BNO3.J.i 157.3PI.00.BNO3.J.r 157.3PI.00.BNO3.K.g Hammer-Aitoff | Spherical 157.3PI.00.BNO3.K.i 157.3PI.00.BNO3.K.r 157.3PI.00.BNW1.J.g 157.3PI.00.BNW1.J.i 157.3PI.00.BNW1.J.r 157.3PI.00.BNW1.K.g 157.3PI.00.BNW1.K.i 157.3PI.00.BNW1.K.r 157.3PI.00.BNW2.J.g 157.3PI.00.BNW2.J.i 157.3PI.00.BNW2.J.r 157.3PI.00.BNW2.K.g 157.3PI.00.BNW2.K.i 157.3PI.00.BNW2.K.r 157.3PI.00.BNW3.J.g 157.3PI.00.BNW3.J.i 157.3PI.00.BNW3.J.r 157.3PI.00.BNW3.K.g 157.3PI.00.BNW3.K.i 157.3PI.00.BNW3.K.r 157.3PI.00.BSE1.J.g 157.3PI.00.BSE1.J.i 157.3PI.00.BSE1.J.r 157.3PI.00.BSE1.K.g 157.3PI.00.BSE1.K.i 157.3PI.00.BSE1.K.r 157.3PI.00.BSE2.J.g 157.3PI.00.BSE2.J.i 157.3PI.00.BSE2.J.r 157.3PI.00.BSE2.K.g 157.3PI.00.BSE2.K.i 157.3PI.00.BSE2.K.r 157.3PI.00.BSE3.J.g 157.3PI.00.BSE3.J.i 157.3PI.00.BSE3.J.r 157.3PI.00.BSE3.K.g 157.3PI.00.BSE3.K.i 157.3PI.00.BSE3.K.r 157.3PI.00.BSO1.J.g 157.3PI.00.BSO1.J.i 157.3PI.00.BSO1.J.r 157.3PI.00.BSO1.K.g 157.3PI.00.BSO1.K.i 157.3PI.00.BSO1.K.r http://ipp0022.ifa.hawaii.edu/ps1sc/denneau/157/hammer.html Page 1 of 3 webviz 10/16/12 11:00 AM MDRM Viewer 136 | 137 | 138 | 139 | 140 | 141 | 142 | 143 | 144 | 145 | 146 | 147 | 148 | 149 | 150 | 151 | 152 | 153 | 154 | 155 | 156 157 158 159 November 3pi fields Show: (Examples: "3pi", "3pi r 1") Previous night Chunk Name 158.3PI.00.ANE1.J.g 158.3PI.00.ANE1.J.i 158.3PI.00.ANE1.J.r 158.3PI.00.ANE1.K.g 158.3PI.00.ANE1.K.i 158.3PI.00.ANE1.K.r 158.3PI.00.ANE2.J.g 158.3PI.00.ANE2.J.i 158.3PI.00.ANE2.J.r 158.3PI.00.ANE2.K.g 158.3PI.00.ANE2.K.i 158.3PI.00.ANE2.K.r 158.3PI.00.ANE3.J.g 158.3PI.00.ANE3.J.i 158.3PI.00.ANE3.J.r 158.3PI.00.ANE3.K.g 158.3PI.00.ANE3.K.i 158.3PI.00.ANE3.K.r 158.3PI.00.ANO1.J.g 158.3PI.00.ANO1.J.i 158.3PI.00.ANO1.J.r 158.3PI.00.ANO1.K.g 158.3PI.00.ANO1.K.i 158.3PI.00.ANO1.K.r 158.3PI.00.ANO2.J.g 158.3PI.00.ANO2.J.i 158.3PI.00.ANO2.J.r 158.3PI.00.ANO2.K.g 158.3PI.00.ANO2.K.i 158.3PI.00.ANO2.K.r 158.3PI.00.ANO3.J.g 158.3PI.00.ANO3.J.i 158.3PI.00.ANO3.J.r 158.3PI.00.ANO3.K.g Hammer-Aitoff | Spherical 158.3PI.00.ANO3.K.i 158.3PI.00.ANO3.K.r 158.3PI.00.ANO4.K.g 158.3PI.00.ANO4.K.i 158.3PI.00.ANO4.K.r 158.3PI.00.ANW1.J.g 158.3PI.00.ANW1.J.i 158.3PI.00.ANW1.J.r 158.3PI.00.ANW1.K.g 158.3PI.00.ANW1.K.i 158.3PI.00.ANW1.K.r 158.3PI.00.ANW2.J.g 158.3PI.00.ANW2.J.i 158.3PI.00.ANW2.J.r 158.3PI.00.ANW2.K.g 158.3PI.00.ANW2.K.i 158.3PI.00.ANW2.K.r 158.3PI.00.ANW3.J.g 158.3PI.00.ANW3.J.i 158.3PI.00.ANW3.J.r 158.3PI.00.ANW3.K.g 158.3PI.00.ANW3.K.i 158.3PI.00.ANW3.K.r 158.3PI.00.ASE1.J.g 158.3PI.00.ASE1.J.i 158.3PI.00.ASE1.J.r 158.3PI.00.ASE1.K.g 158.3PI.00.ASE1.K.i 158.3PI.00.ASE1.K.r 158.3PI.00.ASE2.J.g 158.3PI.00.ASE2.J.i 158.3PI.00.ASE2.J.r 158.3PI.00.ASE2.K.g 158.3PI.00.ASE2.K.i 158.3PI.00.ASE2.K.r 158.3PI.00.ASE3.J.g 158.3PI.00.ASE3.J.i 158.3PI.00.ASE3.J.r 158.3PI.00.ASE3.K.g 158.3PI.00.ASE3.K.i 158.3PI.00.ASE3.K.r 158.3PI.00.ASO1.J.g 158.3PI.00.ASO1.J.i 158.3PI.00.ASO1.J.r http://ipp0022.ifa.hawaii.edu/ps1sc/denneau/158/hammer.html Page 1 of 3 NEO Optimized survey We use a broad w-band filter (g+r+i) to increase sensitivity and have 11% of the observing time Four 45 second exposures separated by 20 minutes in the opposition direction or 7 minutes in the low solar elongation sweet spot directions, using wide filter Opposition search has yielded 536 NEO discoveries, including 41 PHAs Sweet spot search has yielded 28 NEO discoveries, including 11 PHAs September 2013 solar system fields The need for followup observations Pan-STARRS NEO candidates are submitted to the Minor Planet Center Pan-STARRS does not followup its own NEO candidates We follow up some NEO candidates with CFHT PS1 is extremely dependent on other people to followup candidates to produce discoveries Submissions to MPC 2,279,348 asteroid tracklets reported to date 7,223,594 detections 563,836 distinct asteroids 40,357 asteroid discoveries 3,000–6,000 asteroids submitted per night Discovery rate PS1 discovers over 50 NEOs per month when the weather is good The median H magnitude for PS1 NEO discoveries for 2012 and 2013 is 22.4 Other NEO discoveries (mostly from the Catalina Sky Survey) have median H=23.4 Pan-STARRS is good at finding larger undiscovered NEOs that are distant and faint, but less efficient at finding smaller fast-moving nearby NEOs 2012 and 2013 NEO discoveries 200 150 Other 100 F51 50 0 20 25 30 H magnitude 2012 and 2013 NEO discoveries G96 100 F51 80 60 40 703 20 0 20 25 30 H magnitude 2012 and 2013 NEO discoveries 100 80 Other 60 40 F51 20 0 1234 Semi-major axis Comets Pan-STARRS has discovered many comets and is efficient at discovering low levels of activity Five Main Belt Comets have been discovered to date Comet P2013/R3 September ! ! ! ! October Future plans The Pan-STARRS1 Science Consortium survey will finish at the end of February 2014 We are planning to conduct an NEO optimized survey using 100% of the observing time beginning in March 2014 This will enable a much larger area of the sky to be surveyed multiple times per month We can survey further south, reaching to -40˚ Digest scores of NEOs observed by PS1 PS1 NEO 1.0 a 0.9 0.8 0.7 0.6 0.5 0.4 Normalised count 0.3 0.2 0.1 0.0 0 10 20 30 40 50 60 70 80 90 100 NEO digest score Sky coverage with 100% of Pan-STARRS1 Pan-STARRS2 Pan-STARRS2 is nearing completion adjacent to PS1 Adding a second telescope will enable us to survey a large fraction of the sky multiple times each lunation PS2 image of the Crab Nebula Sky coverage with 100% of Pan-STARRS1&2 Camera retrofit The CCDs in the Pan- STARRS telescopes are not ideal Cosmetic quality of some devices is poor Cell structure in CCDs hinders discovery of faster moving NEOs Example of fast moving asteroid detection compromised by cell gaps Camera retrofit Better CCDs would increase our discovery rate by a factor of almost 2.