Reveal Parker Solar Probe's first light data

The right side of this image – the WISPR's internal telescope – has a 40-degree field of view, with its right edge at 58.5 degrees from the center of the sun. The left side of the image comes from the WISPR's outdoor telescope, which has a 58-degree field of view and extends about 160 degrees from the sun. There is a parallax of about 13 degrees in the apparent position of the Sun seen from Earth and Parker Solar Probe. Credit: NASA / Naval Research Laboratory / Parker Solar Probe

A little over a month after the start of its mission, Parker Solar Probe has returned first – light data for each of its four instrument suites. These early observations – although they are not yet examples of Parker Solar Probe's key scientific observations that will approach the sun – show that each instrument works well. The instruments work in tandem to measure the electric and magnetic fields of the Sun, the Sun's particles and the solar wind, and capture images of the environment around the spacecraft.

"All the instruments have returned data that are not only used for calibration, but also capture what we expect them to measure near the Sun to solve the mysteries of the solar atmosphere, the crown," says Nour Raouafi, Parker Solar Probe project scientist. Applied Physics Laboratory, Johns Hopkins University, Laurel, Maryland.

The first closer approach to the Sun mission will be in November 2018, but even now the instruments are able to collect measurements of what is happening in the solar wind closer to Earth. Let's take a look at what they have seen so far.

WISPR (wide field imager for solar probe)

As the sole Parker Solar Probe imager, WISPR will provide even more insight into the solar wind from the solar corona. Consisting of two telescopes, WISPR lies behind the heat shield between two antennas of the FIELDS suite of instruments. The telescopes were covered by a protective door during the launch to keep them safe.

WISPR was commissioned in early September 2018 and took in camera test footage for calibration. On September 9th, the WISPR gate was opened, allowing the instrument to take the first images as it travels to the sun.

Russ Howard, WISPR Principal Investigator at the Naval Research Laboratory, studied the images to determine if the instrument was pointing as expected, using celestial landmarks as a guide.

"There is a very distinctive group of stars on the overlap of the two images. The brightest is the star Antares-alpha, which is in the constellation Scorpius and is about 90 degrees from the Sun, "said Howard.

The Sun, not visible on the image, is far to the right of the right edge of the image. The planet Jupiter is visible in the image captured by the internal telescope of WISPR – it is the light object slightly to the right of the center in the right panel of the image.

"The left side of the picture shows a beautiful image of the Milky Way, looking at the galactic center," Howard said.

The exposure time – that is, the amount of time that light was collected for this image, an interval that can be shortened or lengthened to make the image darker or brighter – is at the bottom . on the low side, in case there is something very bright on our first use, but it's mainly because we look so far from the sun, "says Howard.

As the spacecraft approaches the Sun, its orientation will change, as will the WISPR images. With each solar orbit, WISPR will capture images of structures emerging from the corona. While measurements have already been made by other instruments at a distance of 1 AU – about 93 million miles – the WISPR will be very close, about 95% of the way to the Sun, which will significantly increase the capacity to see what is happening in region with a much finer scale than ever and providing a more pristine image of the solar corona.

ISʘIS (Integrated Scientific Investigation of the Sun)

Credit: NASA / Princeton University / Parker Solar Probe

ISʘIS (pronounced "ee-sis" and including the Sun symbol in its acronym) measures the solar activity associated with high-energy particles, such as coronal mass rashes and ejections. (The other suite of mission particle instruments, SWEAP, focuses on the low energy particles that make up the solar wind.) The two IS àIS energy particle instruments cover a range of Energies for these particles: EPI-Lo focuses on the low end of the energy spectrum, while EPI-Hi measures the most energetic particles. Both instruments collected low voltage data, ensuring that their detectors function as expected. As Parker Solar Probe approaches the Sun, it will be fully powered to measure the particles in the solar corona.

The initial EPI-Lo data, on the left, shows cosmic background radiation, particles that have been excited and skyrocketed in our solar system elsewhere in the galaxy. When the high voltage of the EPI-Lo is activated and Parker Solar Probe approaches the Sun, the measured particles will move towards solar energy particles, accelerated in bursts and coming out of the Sun and the crown.

On the right, the EPI-Hi data show detections of hydrogen and helium particles from its low-energy telescopes. Closer to the Sun, scientists expect to see many more of these particles – as well as heavier elements – as well as particles with much higher energies, especially during solar energy particle events.

"The ISʘIS team is excited about the activation of the instruments up to now," said David McComas, professor of astrophysics at Princeton University and senior research scientist. the suite of ISʘIS instruments. "There are still some steps to go through, but until now, everything is perfect!"

THE FIELDS

The FIELDS suite of instruments onboard Parker Solar Probe captures the scale and shape of electric and magnetic fields in the Sun's atmosphere. These are key measures to understand why the Sun's crown is hundreds of times warmer than its lower surface.

Credit: NASA / UC Berkeley / Parker Solar Probe

The FIELDS sensors include four two-meter electric field antennas – mounted at the front of the spacecraft, protruding beyond the heat shield and exposed to the solar environment – as well as three magnetometers and a fifth shorter electric field antenna. Ride on a boom that extends from the rear of the spacecraft.

The above data, collected during the deployment of the platform shortly after the launch of the spacecraft in August, shows how the magnetic field changes as the arrow moves away from Parker Solar Probe. The first data is the magnetic field of the spacecraft itself, and the instruments measured a sharp drop in the magnetic field as the arrow moved away from the spacecraft. After deployment, the instruments measure the magnetic field in the solar wind, illustrating why these sensors must be kept away from the spacecraft.

Credit: NASA / UC Berkeley / Parker Solar Probe / Wind

In early September, the four electric field antennas located at the front of the spacecraft were successfully deployed and almost immediately observed the signatures of a solar flare.

"During its commissioning, FIELDS measured its first burst of radio from a solar flare," said lead researcher Stuart Bale, from the Space Science Laboratory at the University of California, Berkeley. Such gusts of radio waves can be detected during solar flares – huge eruptions of energy and light – and are associated with energetic electrons that are triggered. This radio burst was captured by the FIELDS electric field antennas, shown above with measurements from the NASA Wind spacecraft (top) for comparison.

"FIELDS is one of the most comprehensive field and wave suites ever deployed in space, and is proceeding wonderfully," said Bale.

SWEAP (solar wind electrons Alphas and Protons)

Credit: NASA / University of Michigan / Parker Solar Probe

The SWEAP suite consists of three instruments: two solar probe analyzers measure electrons and ions in the solar wind, while the solar probe detaches behind the solar heat shield of the Parker solar probe to measure solar wind directly in the sun. After opening the covers, putting under high voltage and internal diagnosis, the three instruments were able to see the solar wind itself.

Due to the position and direction of Parker Solar Probe, the science team expected the Solar Probe Cup to first measure background noise without capturing the solar wind. But just after powering up the instrument, a sudden gust of solar wind suddenly blew into the cut, visible in the data in the form of a red trail. As the spacecraft approaches the Sun, these sightings will be the bread and butter of the Solar Probe Cup and, hopefully, will reveal new insights into the processes that heat and accelerate the solar wind.

Credit: NASA / University of Michigan / Parker Solar Probe

The two Solar Probe Analyzers (SPAN) also detected the solar wind. During the commissioning, the team turned the spacecraft so that the SPAN-A, one of the two SPAN instruments, was directly exposed to the solar wind. He captured about 20 minutes of data (right), including measurements of solar wind ions (top) and electrons (bottom). While SPAN-A and its twin instrument, SPAN-B, will measure the electrons of the solar wind throughout the mission, the spacecraft's orientation now means that SPAN-A will likely spend several more years before capturing again these ionic measurements. Indeed, the solar wind electrons can be measured from any direction, as their low mass and high temperature make their movement much more random, while the much heavier solar wind ions follow a path relatively direct from the Sun.

"SWEAP's performance in solar wind and corona instruments has been very promising," said Justin Kasper, principal investigator of the SWEAP suite of instruments at the University of Michigan. "Our preliminary results, right after the presentation, suggest that we have a set of very sensitive instruments that will allow us to make amazing science as close to the sun as possible."