Rubin LSST: challenges and opportunities
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
LSST Survey Scientist
federica b. bianco
she/her
3,362.2 sq deg w > 1 visits 2,859.5 sq deg w > 2 visits 814.1 sq deg w > 3 visits 782.2 sq deg w > 4 visits 105.8 sq deg w > 5 visits
678 separate images taken in just over seven hours of observing time. Trifid nebula (top right) and the Lagoon nebula, which are several thousand light-years away from Earth. | NSF-DOE Vera C. Rubin Observatory
The Vera C. Rubin Observatory Data Preview 1
June 30, 2025
DP1 release!
>25% DIA detections
>25% DIA detections
new AGNs/TDEs
1 AGN
Galactic variables
SKA
(2025)
17B stars (x10) Ivezic+19
~10 million QSO (x10) Mary Loli+21
~50k Tidal Disruption Events (from ~150) Brickman+ 2020
~10k SuperLuminous Supernovae (from ~200) Villar+ 2018
~400 strongly lensed SN Ia (from 10) Ardense+24
~50 kilonovae (from 2) Setzer+19, Andreoni+19 (+ ToO)
> 10 Interstellar Objects fom 2.... ?)
True Novelties!
Rubin LSST Transients by the numbers
To date 1,299 transients reported to TNS
940 in the last month
Alerce
Ampel
ALERTS HAVE STARTED!
Why not always? We deliver alerts on DDF+Virgo when we run the survey in survey mode (=not engineering tests)
Why not everywhere? Limited templates available - template foorprint increasing
~7M alerts per night
*Conservative ML-reliability scores for now because the infrastructure (Rubin and brokers) is still under development
classifications by ALeRce and Lasair
survey optimization
Rubin LSST survey design
Rubin has involved the community to an unprecedented level in survey design this is a uniquely "democratic" process!
Survey Cadence Optimization Committee
Rubin LSST survey design
2017
80,000
Rubin LSST survey design
Rubin has involved the community to an unprecedented level in survey design this is a uniquely "democratic" process!
2019
80,000
Rubin LSST survey design
Rubin has involved the community to an unprecedented level in survey design this is a uniquely "democratic" process!
2023
80,000
Rubin LSST survey design
Rubin has involved the community to an unprecedented level in survey design this is a uniquely "democratic" process!
2024
80,000
Rubin LSST survey design
Rubin has involved the community to an unprecedented level in survey design this is a uniquely "democratic" process!
2024
2024
80,000
Rubin LSST survey design up to 2018
# pairs of observations (1e5)
time gaps (days)
Eric C. Bellm et al 2022 ApJS 258 13
Proposed 3 intranight obs
2 within 1 hour in different filters
1 at 4-8 hours separation w repeat filter
Intranight color (near instantaneous)
Intranight rate of change (~hour time scales)
Presto-Color, Bianco+ 2019
Introducing Rolling Cadence
Current plan: rolling 8 out of the 10 years
newer simulations ->
<-bad good ->
newer simulations ->
4 – 24 hour gaps between epochs will enable kilonova parameter estimation
Kilonovae in LSST Wide Fast Deep
Andreoni+ 2022a
Rubin ToO program
newer simulations ->
<-bad good ->
Real Observatory Performance??
TDA is most sensitive to efficiency and cannot recover by just adding survey time
Challenges
newer simulations ->
<-bad good ->
Real Observatory Performance??
TDA is most sensitive to efficiency and cannot recover by just adding survey time
newer simulations ->
<-bad good ->
Real Observatory Performance??
TDA is most sensitive to efficiency and cannot recover by just adding survey time
Rubin LSST Science Collaborations
Text
Transietsand variabel stars SC
Shar Daniels
Fast Transients Subgroup Lead
Spectroscopic classification at scale will not be possible
Rest+Andreoni
Fortino
This ensamble distance method excells at identifying out of sample anomalies!
NSF award
2219731
NASA FINESST Fellow
Siddharth Chaini
thank you!
University of Delaware
Department of Physics and Astronomy
Biden School of Public Policy and Administration
Data Science Institute
federica bianco
fbianco@udel.edu
credit: AMNH Dark Universe
federica bianco - fbianco@udel.edu
Rubin ToO program
Andreoni+ 2022b
+80 authors!
PROS:
Large FoV (10 sq deg - easly cover 100 sq deg in full)
6 filters (5 available on any given night)
deep observations (r~24 in 30 sec, up to 180 sec)
public data
federica bianco - fbianco@udel.edu
Rubin ToO program
Andreoni+ 2022b
+80 authors!
PROS:
Large FoV (10 sq deg - easly cover 100 sq deg in full)
6 filters (5 available on any given night)
deep observations (r~24 in 30 sec, up to 180 sec)
public data
CONS:
no custom pipelines planned
80 hours delay in image access
limited sky time (not a PI facility)
Rubin ToO program
https://arxiv.org/pdf/2411.04793
Rubin ToO program
rapid accutare alert release
80 h
Saliency maps: what pixels matter?
search
template
difference
Tatiana Acero-Cuellar
UNIDEL fellow
LSST Data Science Fellow
The Rubin LSST ML-Reliability Score (aka real-bogus)
accuracy 98.06%, purity 97.87%, completeness of 98.27%... on simulated data
- requires instantaneous inference
- limited computational resources (CPU)
- evolving data quality
- limited ground truth data (e.g. no variable stars in training)
DP1
POI/Variables
Ampel
Alerce
Ampel
ALERTS HAVE STARTED!
Why not always? We deliver alerts on DDF+Virgo when we run the survey in survey mode (=not engineering tests)
Why not everywhere? Limited templates available - template foorprint increasing
~7M alerts per night
*Conservative ML-reliability scores for now because the infrastructure (Rubin and brokers) is still under development
classifications by ALeRce and Lasair
ALERTS HAVE STARTED!
The LSST
Science Collaborations
A community of practice funded on principles of Equity, Inclusivity, Cooperation
is a word I am borrowing from Margaret Atwood to describe the fact that the future is us.
However loathsome or loving we are, so will we be.
Whereas utopias are the stuff of dream dystopias are the stuff of nightmares, ustopias are what we create together when we are wide awake
US-TOPIA
thank you!
federica bianco
fbianco@udel.edu