Do Androids Dream

of Exploding Stars

University of Delaware

Department of Physics and Astronomy

Biden School of Public Policy and Administration

Data Science Institute

Rubin Legacy Survey of Space and Time

Deputy Project Scientist, Construction

Acting Head of Science, Operation

federica b. bianco

she/her

Why do we study stellar explosions?

The immutable skies

Bartolomeu Velho, 1568 (Bibliothèque Nationale, Paris)

1549 Oronce Fine, France

From Flammarion's Astronomie Populaire (1880): in Scania, Denmark

Henry III, Tivoli, SN 1054, unknown artist, ca.1450

TED talk - Andrew Connely

←Dimmer Brighter →

0.01 0.1 1 10 100

stellar sexplosions

stellar eruptions

stellar variability

←Dimmer Brighter →

0.01 0.1 1 10 100

Why do we study stellar explosions?

we are made of stars

The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars.

We are made of starstuff.

― Carl Sagan, Cosmos

largest explosion on earth 10,000,000 erg

typical supernova....

Why do we study stellar explosions?

a unique opportunity to study extreme energy events

A new, transformational observatory is about to start building a legacy for humanity

before human-made satellites forever change it

Building a legacy:

The Vera C. Rubin Observatory LSST

the Vera C. Rubin observatory will collect

20Tb of data every night. That is equivalent to

8,000 high definition movies

4,000 hours of tiktok videos

every night for 10 years

Building a legacy:

The Vera C. Rubin Observatory LSST

the Vera C. Rubin observatory will collect

20Tb of data every night. That is equivalent to

8,000 high definition movies

4,000 hours of tiktok videos

every night for 10 years

Building a legacy:

The Vera C. Rubin Observatory LSST

the Vera C. Rubin observatory will collect

20Tb of data every night.

A legacy dataset that belongs to all people in the USA giving access to never before seen corners of the Universe to all

Probing Dark Energy and Dark Matter

image credit ESO-Gaia

Mapping the Milky Way and Local Volume

via resolved stellar population

An unprecedented inventory of the Solar System from threatening NEO to the distant Oort Cloud

image credit: ESA-Justyn R. Maund

Exploring the Transients and Variable Universe

10M alerts every night shared with the world

60 seconds after observation

To accomplish this, we need:

1) Dark Skies - Cerro Pachon Chile

To accomplish this, we need:

1) Dark skies - Cerrp Pachon Chile

2) a large telescope mirror to be sensitive - 8m (6.7m)

May 2022 - Telescope Mount Assembly

3024 science raft amplifier channels

We built the largest camera ever built for the

Vear C. Rubin Observatory

to look farther and wider into the sky than ever before

To accomplish this, we need:

1) Dark skies - Cerro Pachon

2) a large telescope mirror to be sensitive - 8m (6.7m)

3) a large field-of-view for sky-scanning speed - 10 deg2

4) high spatial resolution, high quality images - 0.2''/pixels

Objective: to provide a science-ready dataset to transform the 4 key science area

in 60 seconds:

Difference Image Analysis

in 60 seconds:

Difference Image Analysis + Bogus rejection

Rubin Observatory Data Management Team

federica bianco - fbianco@udel.edu

To accomplish this, we need:

1) Dark skies - Cerro Pachon

2) a large telescope mirror to be sensitive - 8m (6.7m)

3) a large field-of-view for sky-scanning speed - 10 deg2

4) high spatial resolution, high quality images - 0.2''/pixels

5) process images in realtime to produce 10M nightly alerts and offline to produce and catalogs of all 37B objects

Objective: to provide a science-ready dataset to transform the 4 key science area

Are We There YET????!!!!

Eye to the sky…on-sky engineering tests have begun at @nsfgov–@energy Rubin Observatory using the world’s largest digital camera!🔭

April 17 2025

June 23 - 16:00 CEST

In 2025 we will begin observing the sky with 1000 images every night for 10 years

10 stars explode in the universe every second

Until the 1900s we would see 1 in a century

Until the 1980s we would see 1 in a decade

Until the 2010s we would see 1 in a month

With the Vera C. Rubin Observatory we will see 1000 every night !

SDSS (~2000)

LSST-like HSC composite

17B Stars (x10) Ivezic+19

20B Galaxies (x10) Ivezic+19

>1M supernovae (stellar explosions)

~50 kilonovae (today 2) Setzer+19, Andreoni+19

> 10 Interstellar Objects (today 2.... ?)

SDSS 2x4 arcmin sq griz

MYSUC (Gawiser 2014) 1 mag shallower than LSST coadds

17B Stars (x10) Ivezic+19

20B Galaxies (x10) Ivezic+19

>1M supernovae (stellar explosions)

~50 kilonovae (today 2) Setzer+19, Andreoni+19

> 10 Interstellar Objects (today 2.... ?)

True Novelties

How do we study stellar explosions?

with this much data we need Artificial Intelligence

How do we study stellar explosions?

with this much data we need Artificial Intelligence

Grad student

Since 2019 we study the sky (and more!) with AI

Postdoc

Light Echoes

supernova, star eruption, stellar merger

interstellar dust

←this is where you are

Light Echoes

supernova, star eruption, stellar merger, stellar variability

interstellar dust

←this is where you are

Light Echoes

interstellar dust

←this is where you are

supernova, star eruption, stellar merger, stellar variability

Light Echoes

Light Echoes

η-Carinae light echoes

Rest et al. (w Bianco) 2012Natur.482..375R

Light Echoes

η-Carinae light echoes

Frew 2004, Smith & Frew 2011

Light Echoes

η-Carinae light echoes

very faint signal
very rare

Light echoes are like a time machine:

but they are so hard to find!

Xiaolong Li LSST Catalyst Fellow.

change over time
can have almost any shape

AILE: the first AI-based platform for the detection and study of Light Echoes

Award #2108841

Li et al. 2019

AILE: the first AI-based platform for the detection and study of Light Echoes

Tatiana Acero Cuellar is a UNIDEL fellow:

she is Building simulated light echo images to help train AI models

If light echoes are too rare to build large training set to train AI, can we generate realistic light echo images with simulations?

Award #2108841

Multi-city Urban Observatory Network

Studying cities as complex systems through imaging data

Multi-city Urban Observatory Network

Dobler, Bianco, et al 2021, in Remote Sensing

Studying cities as complex systems through imaging data

energy demand and consumption
ecology of flora and fauna
urban metabolism
circadiem rhythms

Multi-city Urban Observatory Network

Testing the performance of MetaAI SAM on astronomical objects

Instead of building our own specialized AI, can we adapt the models that the industry produces?

That would save a lot of computational resources and computational resources have an environmental footprint!

Award #2123264

Rodiat Ayinde and Tatiana Acero Cuellar are applying the computer vision models they developed for astronomy to geography

What's even harder to study than stellar explosions?

Shar Daniels is a NSF Graduate Research Fellow.

They use telescopes and cameras in innovative ways to show the stars in their time evolution at milliseconds rate

and uses cutting edge AI (transformers) to discover new physical phenomena

NSF Graduate Research

Fellowship Program

time: 1 pixel = 3.0 milliseconds

space: 1 pixel = 1 arcsecond

What's even harder to study than stellar explosions?

Any phenomenon that changes rapidly, in less than hours, is a technological challenge in astronomy

What's even harder to study than stellar explosions?

Stellar flares are short lived (~minutes) brightening events caused by magnetic reconnections in stars' atmospheres. Stellar flare impact planetary habitability. Fast and unpredictable, they are hard to study and their physical properties, like temperature, are poorly constrained.