April 2019 - WinStars 3

Parker Solar Mission: learn more about the solar corona

Launched on August 4, 2018, the Parker Solar Probe (PSP) has the mission of studying the Sun for 7 years. Placed in a elliptical orbit, with its perihelion located at less than 0.17 astronomical units (AU) and its aphelion at the orbit of Venus, this NASA mission is full of achievements. Equipped with an efficient thermal shield that protects its structure from the flux emanating from the Sun and will raise the temperature to 1400 K at times, the probe is equipped with four instruments that will study the solar corona.

PSP in WinStars

Indeed, the corona remains poorly understood even today. We know almost nothing about the accelerating mechanisms of the particle flux escaping from the upper atmosphere (the solar wind), nor about the origin of the high temperatures of the corona (1 million degrees K), which are a hundred times higher than those observed at the surface of the star.

A wide-angle coronagraph will capture three-dimensional images of the corona and the inner heliosphere. The FIELDS instrument will measure electric and magnetic fields, radio wave emissions, and plasma waves. ISIS (Integrated Science Investigation of the Sun) will provide more information about the characteristics of particles present in the solar atmosphere and the inner heliosphere, accelerated to high energies (from 10 keV to 100 MeV). Finally, the SWEAP (Solar Wind Electrons Alphas and Protons) instrument will study the electrons, protons, and helium ions that make up the solar wind.

On April 4, 2019, the probe ventured to within 25 million kilometers of the Sun, moving at a relative speed of 343,000 km/h with respect to it, making it the fastest object in human history. In 2023, PSP will come within 6 million km of the Sun.

By installing the Parker Solar module in WinStars, it is possible to visualize the probe’s position in real-time and follow the 24 planned orbits to uncover the secrets of our star’s atmosphere.

Gaia Data Release 2

After several weeks of effort, the second catalog of the Gaia mission has been successfully integrated into WinStars.

As a reminder, the Gaia mission aims to map a portion of the Milky Way (1%) in 3D by assessing the proper motion of the celestial bodies listed. This colossal task is carried out by a satellite positioned at the Lagrange 2 point, which performs 500 million measurements daily.

The previous catalogs, such as Sky2000, UCAC4, and I/280B, have been replaced to make way for the 1.7 billion stars featured in this second edition, published in April 2018, one year ago.

Since it is not reasonable to retrieve all of the data from DR2, WinStars only uses right ascension, declination, parallax, proper motion, and G magnitude for objects with a magnitude lower than 13. Beyond this limit, the program only retrieves hourly coordinates and magnitude.

A version 3 in 2022

The Gaia mission’s measurement campaign continues, and a version 3 of the catalog is expected in 2022 with increased data accuracy.

We are only at the beginning of the mission. In the long run, the entire structure of our galaxy, its dynamics, and evolution will be better understood through the analysis of this vast amount of information.

Scientific data freely accessible thanks to the CDS

I would like to conclude by acknowledging the work of the Centre de Données de Strasbourg, a true virtual memory of the sky, which makes available to everyone the data collected by the largest observatories and collaborations like Gaia. This is how measurements from a satellite located two million kilometers from Earth can be found in WinStars just a few months later.

WinStars uses the Gaia DR2 catalog to display stars up to magnitude 20, as seen here with the globular cluster Messier 13.

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