Concept explainers
(a)
The wavelength of the emission, if the Institute of Space and Astronautical Science (ISAS) in Japan proposes to place a radio telescope at an orbit higher than that of the HALCA telescope. The astronomers propose to use this combination of telescopes to study radio emission at a frequency of
(b)
The angular resolution that can be achieved by assuming the baseline to be the effective diameter of a radio telescope array, if the Institute of Space and Astronautical Science (ISAS) in Japan proposes to place a radio telescope at a higher orbit than that of the HALCA telescope. Astronomers propose to use this combination of telescopes to study radio emission at a frequency of
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Universe
- The HST cost about $1.7 billion for construction and $300 million for its shuttle launch, and it costs $250 million per year to operate. If the telescope lasts for 20 years, what is the total cost per year? Per day? If the telescope can be used just 30% of the time for actual observations, what is the cost per hour and per minute for the astronomer’s observing time on this instrument? What is the cost per person in the United States? Was your investment in the Hubble Space telescope worth it?arrow_forwardSuppose you send a probe to land on Mercury, and the probe transmits radio signals to earth at a wavelength of 52.0000 cm. You listen for the probe when Mercury is moving away from Earth at its full orbital velocity of 48 km/s around the Sun. What wavelength (in cm) would you have to tune your radio telescope to detect that signal? Use the doppler shift formula Note: the speed of light is 3.0 ✕ 105 km/s. Give your answer to at least four decimal places.)arrow_forwardThe angular separation in degrees of two objects is (physical separation × 360°) / (2 π × distance). If an individual was observing our solar system from Castor at a distance of 7.2 light years. What angular resolution, in arcsecond, is needed to resolve the Sun-Jupiter system (5.46 AU) as distinct points of light?arrow_forward
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- You are the leader of the international Event Horizon Telescope, a collaboration of radio astronomers who want to take a picture of the black hole at the center of the Milky Way (Sag. A*). That black hole has a mass of about 4.1 million solar masses and is about 8 kpc away. If you are observing with a radio wavelength of about 1 mm, what effective diameter of your radio interferometric array is needed in order to just resolve the diameter of the Sag. A* black hole event horizon. (Assume the black hole is non-spinning, so its diameter is twice the event horizon radius.) Express your answer as a multiple of the Earth's radius. [Hint: you will need to recall and combine three formulas introduced throughout this course, including one about how big a black hole is, one about the criterion for resolving objects, and another that relates distance, sizes, and angles.] There really is an Event Horizon Telescope, and they are responsible for the first image of a black hole in the galaxy M87…arrow_forwardWhat diameter telescope is needed to resolve the separation between an Earth-like planet and its star at 550 nm if the linear separation between them is 1 AU and the star system is 1 pc from Earth? (Give your answer in m.)arrow_forwardWhat are the different types of remote spectroscopy? List them all with a explanationarrow_forward
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