The satellite is pointed toward the sun, and constantly in rotation, which provides a serendipitous bit of side research: by monitoring the limb of the sun on its four second rotation cycle, RHESSI’s Solar Aspect System (SAS) has produced ten years worth of precise measurements of the sun's diameter.
Artist rendition of RHESSI spacecraft in orbit. Credit: NASA
This has already provided scientists with one of the most accurate measurements of what's called the oblateness of the sun, which is the difference between the diameter from pole to pole and the equatorial diameter. With the new data obtained during the Venus Transit on June 5-6, 2012, the RHESSI team hopes to improve the knowledge of the exact shape of the sun and provide a more accurate measure of the diameter than has previously been obtained.
For one thing, the sharpness of the Venus disk as it crosses the sun will help determine the detailed optical properties of the telescope and calibrate the instrument’s so-called plate scale, the exact angular size of each pixel. With this improvement in hand, RHESSI can re-calibrate its already highly accurate observations of the sun's horizon. To further this aim, the science team has set the instrument to look at 64 pixels across the sun's limb, rather than its customary four.
The RHESSI team has hopes that they may be able to provide an unprecedentedly accurate measurement of the sun's size.
With ten years of solar diameter measurements as well as observations of the Venus Transit in 2004 – a time when the sun's activity was decreasing toward solar minimum, as opposed to now when the solar activity is increasing as it moves toward solar maximum predicted for 2013 – the science team hopes to compare the sun's size then and now to see if perhaps it varies with the solar cycle.Karen C. Fox
Susan Hendrix | EurekAlert!
First results of NSTX-U research operations
26.10.2016 | DOE/Princeton Plasma Physics Laboratory
Scientists discover particles similar to Majorana fermions
25.10.2016 | Chinese Academy of Sciences Headquarters
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
26.10.2016 | Physics and Astronomy
26.10.2016 | Earth Sciences
25.10.2016 | Earth Sciences