Category: Non classé

I just put online a new bug tracker. The previous system was no longer updated for years and had become incompatible with php 8.x.

If you want new features in the program or just want to report a problem, please use this new interface as a priority. 

The address has not changed, it is still here:
https://belacqua-labo.ovh/winstars3/bugtracker

A small interview has just been published on the appoftheday website. It’s happening here:

WinStars 3 – Astronomy Review & Download – App Of The Day (downloadastro.com)

Happy reading!

But the main feature of this version is the introduction of a new symbol (the letter i in red) indicating a link to an online article on theconversation.com.

These high-quality popular science articles are written by astronomers or physicists, and I am reproducing them here with their permission. Many thanks to all these researchers who devote part of their time to informing the general public about the current state of research in astrophysics.

This version also fixes an issue with the Gaia EDR3 catalog, which was no longer accessible due to the URL change of the Astronomical Data Center of Strasbourg.

And finally… W3 is nearly 100,000 lines of C++ code that I maintain alone. It’s more than 3 GB of astronomical data stored on two servers that power the software. The program is capable of displaying over a billion objects. So, you can encourage me to continue by purchasing the full version, or by leaving a positive comment on Google Play, etc.

Thank you for your support!

You can find us on the mathstodon.xyz server by following this link: https://mathstodon.xyz/@winstars

However, this solution is not optimal. The elements of the landscapes are still too approximate in places, and the files are too large. Later on, I will use the tessellation technique to improve rendering quality and reduce file size.

Since the first discoveries by Aleksander Wolszczan and Michel Mayor and Didier Queloz in the 1990s, thousands of exoplanets are now listed in catalogs. The Corot, Kepler, and Tess space missions have significantly increased their numbers in recent years, and the James Webb Space Telescope is also contributing to their direct observation. We can mention the example of HIP 65426 b and the first image of an exoplanet obtained in mid-infrared. This is a very young giant exoplanet, about 15 million years old, located 90 astronomical units from its star. With an estimated mass of about 7 times that of Jupiter, it was discovered using the European instrument SPHERE at the Very Large Telescope in 2017.

The complete list of exoplanets can be accessed from the program by entering the command “list exo” in the search bar. You can also locate an object by simply entering its identifier. The database used by W3 comes from the exoplanet.eu website and will be updated every week.

The revision 3.0.268 also proposes to follow the position of the Orion capsule in real time. The objective of this Artemis 1 mission is to return to the Moon in 2025 and ultimately maintain a more or less continuous human presence there.

The next revisions of W3 will include the ability to visit these exoplanets in the 3D Navigation mode. I also plan to add 3D landscapes to the planetarium mode (for fun) and many more features… But I’ll tell you more about that later.

I am continuing to improve the program’s stability. It is therefore essential to report any operational anomalies using the bugtracker or forums (here and there₁). Thank you for your participation!

(1) A big thank you to Sora Kozima for creating this forum on discord.com!

Orbiting the Sun, comets and asteroids provide us with valuable information about the constitutive elements of planets. Having presumably evolved little since their formation 4.6 billion years ago, they appear as distant remnants of the primordial nebula that gave birth to our solar system. For this reason, these small celestial bodies have increasingly attracted the attention of scientists over the past few decades, who have developed numerous techniques to learn about their physical characteristics (shape, configuration, surface, geology, rotation period, etc.). Of course, there have been some interplanetary missions that have allowed us to approach them (such as Galileo, NEAR Shoemaker, Dawn, or Rosetta), but these missions are far too complex and costly to consider exploring the 390,000 asteroids cataloged so far in this way.

Also, when one of these objects is located less than two million kilometers from Earth, it is sometimes possible to use powerful radio telescopes to image its surface and determine its size, morphology, rotation speed, and whether or not it is accompanied by one or more small satellites.

This is how asteroid 2021 PJ1 was observed on August 14, 2021, with the 70-meter antenna of the Deep Space Network located in Barstow, California. And it is with the Arecibo radio telescope that most radar imaging studies have been conducted, reaching a catalog of a thousand objects today.

However, the photometric method of light curves is most commonly used. Asteroids have such modest diameters (< 1000 km) that it is impossible to resolve them optically with the largest ground-based telescopes. But by observing variations in brightness of asteroids over about ten hours, one can mathematically reconstruct the object’s geometry and determine its rotation period. These light curves, which show minima and maxima as well as periods, provide clues about an elongated or spherical shape, surface irregularities, the presence of large craters, or the existence of a companion.

To complete this presentation, I can only recommend reading two articles by Stéphane Fauvaud on this subject, which you will find at the bottom of the page. I had the pleasure of accompanying him to the Pic du Midi observatory over the past ten years on missions to establish these light curves. Some of them now allow us to reproduce in 3D several asteroids present in W3.

For the time being, only objects with a number < 100 are represented in 3D in the paid version.

• Properties of slowly rotating asteroids from Convex Inversion Thermophysical Model.
• VLT/SPHERE imaging survey of the largest main-belt asteroids:
  Final results and synthesis : aa41781-21

The Raspberry Pi is a credit card-sized nano-computer, designed by professors from the Computer Science Department at the University of Cambridge.

This computer was created with the goal of democratizing access to computers. Sold for less than €40 in its base version, it supports several variations of the free GNU/Linux operating system and also works on proprietary operating systems, such as Windows 10 IoT Core and Google Android Pi.

Ode to Commodore

For a few weeks now, the Raspberry Pi Foundation has been offering a version equipped with a keyboard reminiscent of popular computers from the 1980s, such as the Commodore 64, the Amiga 500, and the ZX Spectrum. It is robust and features a passive cooling system, making it an interesting ally for your astronomical observations.

WinStars 3 is now available for free on these little machines. The installation may seem complex, but all you need to do is methodically follow these instructions in a terminal.

The program runs at 20 frames per second on the Raspberry Pi 400, and it is possible to improve performance by overclocking the computer. My Raspberry Pi 400, which operates at 2000 MHz, never exceeds 40°C (104°F) when I use W3.