The BRITE Space Telescope: Using a Nanosatellite Constellation to Measure Stellar Variability in the Most Massive Stars
- Paper number
IAC-06-B5.2.07
- Author
Mr. Norman Deschamps, University of Toronto Institute for Aerospace Studies, Canada
- Coauthor
Mr. Cordell Grant, University of Toronto Institute for Aerospace Studies, Canada
- Coauthor
Mr. Daniel Foisy, University of Toronto, Canada
- Coauthor
Dr. Werner Weiss, University Vienna, Austria
- Coauthor
Dr. Anthony Moffat, Canada
- Coauthor
Dr. Robert E. Zee, University of Toronto, Canada
- Year
2006
- Abstract
The Bright Target Explorer (BRITE) mission is a Canadian/Austrian nanosatellite constellation that will examine the apparently brightest stars in the sky for variability using differential precision photometry. This constellation consists of four low Earth orbiting nanosatellites. Each of the satellites are identical except that they are divided into pairs, with each pair having a different optical filter. To accomplish the science objective, each BRITE satellite utilizes a number of new, innovative technologies including reaction wheels, star tracker and optical telescope, all sized and designed around Space Flight Laboratory’s 5-kilogram, 20x20x20cm CanX nanosatellite bus. The nanosatellite reaction wheels and star tracker currently under development by Dynacon Inc. enable arcminute-stable attitude control for each BRITE satellite and provide the attitude accuracy and stability necessary for long duration photometry. The BRITE science instrument is a low power CMOS imager coupled with a lens system designed to provide a telecentric defocused image optimized for observing stellar intensity with an accuracy of 1mmag per datapoint per orbit down to a visual magnitude of +3.5. The optics will have a small (< 30 mm) aperture and a maximum length of 100 mm in order to fit within the nanosatellite bus. The telescope optics in each satellite will be designed to work with either a visual/red or blue/UV filter without a change in the lens system. Internal baffling will be used to reduce stray light and maximize observation time. Each BRITE satellite will observe a region of interest for up to 100 days or longer, allowing measurement of stellar variability that is on the order of hours to several weeks. Photometric measurements will use multiple sub-rasters co-added over a 15 minute observation window during each orbit. Each image will have an error in the differential photometry less than 0.1% (1000ppm) and an error amplitude spectrum no greater than 20ppm over measurement periods longer than a month. This gives BRITE a photometric precision that is at least 10 times better than current ground-based observations for bright stars. This paper summarizes the science objectives of the BRITE mission, details the design requirements of the telescope to meet those objectives and describes the ongoing process of incorporating the telescope into SFL’s 5-kilogram nanosatellite bus.
- Abstract document
- Manuscript document
IAC-06-B5.2.07.pdf (🔒 authorized access only).
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