Vera Rubin's Super Telescope Will Give Us the Biggest Movie of Our Universe: "It's a Revolution"

When you think of telescopes, you always wonder how far they can see with their powerful lenses. The newly opened Vera Rubin , built in the mountains of Chile where the clear, dry air creates a paradise for astronomers from around the world, does both .

Its "eye" moves quickly and can photograph large areas of sky in a few hours, covering the entire southern hemisphere sky in 3-4 nights .

Over the course of ten years, it will map the entire sky 800 times in visible, near-infrared, and near-ultraviolet light, with the world's largest photographic sensor (3,200 megapixels) and an equally record-breaking lens.

It will give us back " the greatest film of our Universe " says Sara (Rosaria) Bonito , 48, a scientist at the National Institute of Astrophysics , at the Palermo Observatory, and who represents the INAF on the Board of Directors of the LSST Discovery Alliance of the Vera C. Rubin Observatory. Objective: to study how dark matter and energy bend and accelerate the Cosmos, but also to observe everything that moves or changes brightness in the sky, discover new objects, stars, asteroids and comets. And, like a sentinel, warn the international community of what is happening. "A revolutionary project also for the new generations".

Dr. Bonito, what new discoveries was the Vera Rubin Observatory designed to make?

It is a project born twenty years ago to focus on the study of dark energy and matter. The idea was to put together for the first time three great qualities of telescopes: a large field of view; speed, the ability to quickly move the telescope and therefore take a picture of the entire southern sky every three days, therefore in a very short time; and that of being able to observe very faint and therefore very distant objects. Put together they have revolutionized over time a little the purposes for which it was originally designed. So now it is possible to use this revolutionary project for countless fields. Our solar system, our galaxy, the Milky Way, plus everything that is transient and viable in the sky.

We talked about "astrocinematography". What does that mean?

This means we will have the greatest movie of our universe, in space and time: a dynamic vision of the way we are able to investigate the Cosmos. Because rare, unusual, interesting events that can vary, together with persistent ones, can provide us with a deep and detailed map of our entire Universe.

We are used to looking at the sky of "fixed stars", the photos of large telescopes, and think of everything as immobile, or that it changes over times much longer than a human lifetime. So what are transient objects?

Almost all astrophysical objects can be considered transitory and variable. Objects already known on which we can further investigate, or rare objects, some are for example a supernova explosion, kilonovae, mergers of very dense stellar objects, such as black holes and neutron stars. Another example are stars that are forming, the first image captured by Vera Rubin that has been distributed is a region of star formation, in which they can vary on different time scales, from minutes to days up to months or the entire duration of the survey, which is ten years. If an astrophysical object undergoes a change, in position or just in brightness, Rubin will capture it in a very short time.

How will he do it?

The Rubin Lsst is the largest digital sensor ever built and so is its largest lens: they have already entered the Guinness Book of Records. The 3,200 megapixel camera is the size of a small car. The field of view is very large, corresponding to about 45 full moons in the sky, to display a single image you would need 400 high definition televisions. Every night we will have 23 terabytes of data, a new era will open.

The telescope is dedicated to astrophysicist Vera Rubin, whose studies led to the hypothesis of the existence of dark matter to explain the behavior of galaxies.

The large field of view and ability to observe faint and distant objects will allow it to observe galaxies to answer questions about how dark matter influences their evolution. And how energy can cause galaxies to separate as they move away from each other. With specific measurements it will be able to test these theories and formulate possible alternative explanations.

Vera Rubin will not only observe the distant cosmos. What will we study inside our own galaxy, the Milky Way?

Inside the Milky Way we can study for example the regions of star formation, and therefore explore the physical mechanisms that lead to the birth of stars. It will be possible to capture the stars at the moment in which they are forming to understand even more the physical processes at play, Rubin will be an ideal laboratory.

And in our Solar System?

Many new objects will be visible. Rubin will be perfect for making a census of our Solar System, it will show us millions of new asteroids and comets.

What do the first revealed images tell us?

There is an image of the Trifid and Lagoon nebulae. These are star-forming regions where you have a combined image of more than 600 images, an exposure of just over seven hours, with a truly exceptional level of definition, you can see details, such as filaments, that were too faint to be observed until now. And it is beautiful. Then there is the Virgo cluster, spiral galaxies, galaxies that are merging, many galaxies in the background and stars of our galaxy.

Is it true that the new telescope will also be a kind of sentinel?

When something changes, it is associated with an alert that is distributed to the world. And this allows us to start a whole chain that we call observational follow-ups, with other instruments and characterize the physical processes at play and from all points of view.

What happens when an alert goes off?

When an image is acquired where there is a difference, for example if they are supernovae, or objects that are moving, such as asteroids, young stars that have increased their brightness greatly in an eruptive way, or variable stars, an alert will be issued within 60 seconds to the entire world. With twenty terabytes, we are talking about 10 million alerts per night. When one of these is of interest to a certain scientific community, a working group, these will be distributed through what are called brokers.

So other scientists can point their telescopes and study what Vera Rubin is pointing out to them.

Speed ​​is a key strength. I am thinking, for example, of fields such as kilonovae where the follow-up must be fast in order not to miss the peak of the object's variation, especially if they are so-called "rare transients".

What role does Italy have in this program?

Aside from the observatory, the Rubin Project, which is American built in Chile, there are also two other very important parts: one is called Lsst Discovery Alliance, an international organization of all the member institutes from all over the world, Inaf for Italy. And then the scientific collaborations, organizations of communities of scientists in the world that deal with optimizing the observation strategy, to exploit a telescope with these potentialities; what we call in-kind projects to have access to the data in exchange for our skills in developing software for data analysis, or use of Inaf telescopes, or international data centers. Inaf has a great role, in particular Massimo Brescia of the University of Naples and Claudia Raiteri of the Turin Observatory, they manage the contributions of the Inaf researchers.

Much is expected from this telescope.

In my opinion, it is a great investment for the new generations. I invested in Ruby years ago, when I was still precarious. An international project like this is truly a collective effort with interdisciplinary techniques. It will allow us to know our universe even better, to answer questions that we do not yet know we should ask ourselves. And it will be a great inspiration for students who now decide to start scientific paths.