New Horizons brings new helpers to visible stars
Introduction: After the main mission of "New Horizons" is completed, it will become the first mission to explore Kuiper Belt objects and will become part of a longer-distance measurement project. Out of the solar system.
——The New Horizons team is looking forward to your joining, let’s measure the star distance together!
If you have a light scope and imager, NASA wants your help in completing a record-breaking measurement.
A design concept of New Horizons, rushing out of the solar system.
NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute / Steve Gribben / Alex Parker
As April approaches, NASA intends to use the New Horizons spacecraft’s unique location— Taking the sun as the starting point, the farthest distance ever, nearly 47 astronomical units - as the baseline for parallax measurement.
Since its launch on January 19, 2006, New Horizons has been flying for more than 9 years, and performed its historic mission on July 14, 2015 - flying over Pluto and Charon . Its initial mission has ended, and New Horizons will become the first mission to have the opportunity to explore the Kuiper Belt, which was discovered in 2014. From "Sky" MU69 in 2014, to the New Year of 2019, it has flown 2,200 miles (approximately 3,541 kilometers). Now, New Horizons will become a member of the space ranging project to measure the distance of more distant objects.
What is parallax?
Parallax works by determining an object's visible position in the sky from two different locations, without any offset of the object compared to a more distant background source. The longest traditional baseline is measured to be 2a.u.; the detector is aimed at a star near the side of 's earth orbit that is close to the earth, and is aligned again from the other side of the earth 6 months later.
Although Han Solo in Star Wars once said in a spaceport tavern, parsec is a tool for measuring distance (distance measurement), 1 parsec = 3.26 light years, measuring a planet How close does a star need to be to the 2a.u baseline to produce 1 arc second of displacement in space.
There is no star close enough to the solar system to show such a large displacement - the stars are so far away that their distance from the Earth is almost impossible to measure (it's okay to say it's impossible). Astronomer Friedrich Bessel completed the first successful parallax measurement experiment in 1838, measuring a 314 millisecond displacement of Cygnus 61 and positioning it at a distance of 10.4 light-years. (There is an error of about 1 light-year from the currently recognized distance.)
Measurement Target
The New Horizons team's upcoming parallax experiment will use detectors from the spacecraft and from Earth to measure the distance between two nearby stars.
One target for each hemisphere: Proxima 4 Centauri for the southern hemisphere, and Wolf 359 for the northern hemisphere. Wolf 359, which has an apparent magnitude of 13.5, is located in an area with sparse stars in the constellation Leo, about 7.9 light-years away from the Earth and close to the ecliptic. The more familiar Proxima Centauri is 4.2 light-years away from the solar system and is the closest star to the solar system. It is located in the starry galaxy . Both stars are at an angle to New Horizons' flight path, which is heading toward the constellation Sagittarius.
*Picture: New Horizons’ flight path. NASA
"The trajectory of New Horizons determines the parallax," said Todd Lauer (National Optical Astronomy Observatory). "Stars have their trajectories, and even when they are very close, they create an associated small parallax. Perpendicular to it Stars are affected by the overall effects of the large baseline."
Target stars that appear seasonally from Earth during April should also be considered. One candidate, Ceti UV star , was excluded due to its seasonal appearance, a star with excellent visibility in the northern autumn. The
Long Range Reconnaissance Imager (LORRI) detector camera will image the two star fields from New Horizons' vantage point in the Kuiper Belt.LORRI is very close to the space-based 8-inch aperture reflecting telescope .
*Picture Engineers install LORRI on New Horizons. NASA
While the results of the project may not necessarily lead to any substantial scientific breakthroughs, this experiment will demonstrate the feasibility of such long-baseline parallax measurements. And unlike the ground baseline measurement, which takes 6 months, the measurement of the parallax project will be performed at the same time. In this way, the negligible movement of the two target stars against the background of the starry sky can be ignored. The
experiment will also demonstrate how spacecraft flying out of the solar system can use nearby stars to perform fixed-point displacements in space.
* Figure Target star field: Wolf 359 (bright star near the center). The green circle is the best position for New Horizons to observe stars. William Neal/University of Alabama/SARA Observatory
The best time to observe the target star is April 22-23. The New Horizons Parallax Project provides full detection details, including time and starfinder maps. The observation time is applicable to North America (Wulf 359), Australia and South America (Proximal Centaur).
* Figure Target star field: Proxima Centauri (the bright star near the center). The green circle is the best position for New Horizons to observe stars. William Neal/University of Alabama/SARA Observatory
This is not the first time amateur astronomers have supported the New Horizons team. In 2017, the observation expedition team measured a star hidden in the "sky". The data revealed the double-lobed structure of Kuiper Belt objects, which was confirmed after New Horizons flew through the region in 2019.
"The remaining fuel of New Horizons may only be enough for it to explore the last celestial body (also the third goal of its research), which will take almost 2-3 years starting from this summer." Alan Sturt (NASA Southwest Research Institute) revealed, "It also took four years for 'Sky' to be discovered."
must participate in this historic observation, New Horizons will fly out of the solar system!
BY: David Dickinson
FY: ISHUCA·Liu
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