http://phastt.net/potentially-hazardous-asteroid-search-tracking-telescope-network-press-release/http://phastt.net/projects/http://phastt.net/about/The PHASTT projects are built on our desire to quickly (and cheaply) design and deploy wide-field telescopes to aid in the search and characterization of small, undetected asteroids and comets. The PHASTT (Potentially Hazardous Asteroid Search & Tracking Telescope) network will, initially, consist of two telescopes – an f/1 Baker-Nunn camera situated near Arequipa, Peru and a 50cm f/3.6 astrograph located near the town of Ager in the Catalonia province of Spain.
PHASTT-1 will be a commercial, off-the-shelf astrograph with a diameter of 50cm and a focal ratio of 3.6. Equipped with a large-format CCD camera, this telescope will image an area of about 1.4 square degrees allowing it to observe a large number of asteroids per night. In order to characterize asteroids, a special eight-colour filter set will be mounted.
PHASTTER (Potentially Hazardous Asteroid Search & Tracking Telescope for Education and Research) will, as its name implies, be faster than PHASTT-1. Much faster. With the same 50cm aperture and an incredible f/1 optical design, the modified Baker-Nunn will capture more than 14.5 square degrees of sky in each image. This means that it will have one of the largest, single-CCD field-of-view in the world!
In the future (after PHASTT-1 is operational) we plan to expand network capabilities greatly. For now, we’ll call it PHASTT-4ward. We don’t have all of the technical details sorted out yet but we can say that it will combine a pretty cool optical design with a truly innovative software solution. On the hardware front, a 4 telescope setup with 50cm f/2 optics means that a single site will cover the same field of view as the incredibly capable PHASTTER design. By doing so, the advantages will be clear: higher resolution and a better limiting magnitude – two very important features that will help us find the small, faint asteroids that we’re after before they impact the Earth.
PHASTT-1
What: 50cm f2-f3.6 astrograph equipped with an FLI ML-09000 CCD camera and ECAS filter set. Although an f3.6 optical tube is off-the-shelf equipment from ASA, Both ASA and Officina Stellare can provide faster custom designs.
Where: Montsec (near the town of Ager, Catalonia), Spain.
Why: To track and characterize possibly hazardous asteroids and comets. Also, capable of systematic, small area searches to a magnitude of about 22.
PHASTT-1 Technical Specifications
•Primary Diameter: 50cm
•Focal Ratio: 3.6(ish)
•Corrected Image: 90mm
•CCD Chip: KAF-09000
•Plate Scale: 0.8-1.7″ per pixel (0.090-0.143″/um)
•Image Area: 1.4 square degrees
•Filters: Clear + ECAS set
•Limiting Magnitude (w/out filter): ca. 21.6 (30s) / 22.1 (60s)
•Limiting Magnitude (w/ filters): ca. 19-20
•Slew Rate: >10 deg/s
•# Images/Hour: 50-90 (up to 1500 sq. degrees / night!)
•# asteroids/image on ecliptic: up to ca. 75
•Control System: Software Bisque, ASCOM- or INDI-compliant (TBD)
Technical Specifications
•Aperture: 20″
•Optical Design: modified Schmidt with additional field-flattening and corrective optics
•Focal Ratio: a bit under f/1
•Corrected Field-of-View: up to 20 sq. degrees
•Camera Type: off-the-shelf with custom front-end
•Area per Image: 7-18 sq. degrees
•Plate Scale: 3.9″/pixel (for 9um)
•Limiting Magnitude: 17-19+
•Number of stars per image: up to 10′s of thousands!
•Typical Exposure Length: 15-30s
•Image Rate: 60-80 per hour
•Control System: The Bisque TCS or ASCOM-/INDI-compliant Arduino-based (TBD)
In order to help explain one of the most important features of the Baker-Nunn camera, we’ve created the image below. The full frame (green square) is an actual image taken with the refurbished TFRM Baker-Nunn camera at Montsec. It is very large and easily images the Orion and Horsehead nebulas in a single frame. For comparison, several squares are drawn to represent the fields captured by a ‘normal’ 50cm scope (blue), a PHASTT-1 50cm (red), and a PHASTT-1 40cm (orange). It is this large field that increases search efficiency and makes PHASTTER an ideal transient search telescope.
Dr.
Octavi Fors is a Spanish astronomer who will soon be joining the Qatar Energy and Environment Research Institute (Qatar Foundation). Over the past 8 years, Dr. Fors has worked at the University of
Barcelona and
Fabra Observatory refurbishing the
TFRM Baker-Nunn and overseen its operation in the context of TFRM-PSES, a Super-Earths survey which is being conducted with the telescope. His professional interests include robotic astronomy, searching for exoplanets, image processing, and high angular resolution measurement using lunar occultations.
