<p>TLDR: The alerts from the Vera C. Rubin Observatory will be public to everyone but the alert rate and packet size are too large to distribute by email and will be distributed through alert brokers.</p>
<p>The <a href="https://www.lsst.org/" rel="noreferrer">Rubin Observatory</a> will indeed carry out a survey of the visible sky every night from it's location on a mountaintop in Chile. However the number of alerts and the amount of information needed to be transmitted per alert in order to understand the source that produced the alert and do science on it is much too large to be simply sent out to whoever is interested and will instead flow through a series of 7 <a href="https://www.lsst.org/scientists/alert-brokers" rel="noreferrer">Alert Brokers</a> that will ingest the (compressed binary) alert packets and serve them to users.</p>
<p>Rubin, during the course of it's Legacy Survey of Space and Time (LSST) operates by repeatedly surveying pre-defined patches of sky. This is called a <em>visit</em> and will consist of either 2x15s or 1x30s exposures (TBD based on camera performance and amount of satellite constellations). These visits occur every approx. 42s to somewhere on the sky with the same patch of sky revisited ~40 minutes later (to find/eliminate moving asteroids). The 2x15s exposures are combined together and differenced with a previously constructed deeper reference image of the same patch of sky combined from multiple exposures. Everything that is different (changed in brightness or position) between the new image and the reference that passes certain cuts, gets sent out as an alert packet. The aim is for all of this processing to occur 60s after shutter close.</p>
<p>Estimates of the <a href="https://dmtn-102.lsst.io/" rel="noreferrer">number of alerts</a> are uncertain (since no surveys to LSST's depth have been performed) and vary <em>a lot</em> depending on the galactic latitude and stellar density. The range spans from the approximately 1000 the OP quotes (<em>Note</em> this 1000 is per-<em>visit</em>, not per night) to ~40,000 alerts per visit. Depending on how well the actual finished telescope performs, the expectation is ~900 visits per night. This means between 0.9 and 36 <em>million</em> alerts per night. Each alert packet contains a <a href="http://ls.st/dpdd" rel="noreferrer">lot of details</a> (see Section 3.5) on position, shape, brightness, errors, postage stamps etc and is ~82kB in size. This stream is too large to give to everyone who wants it and you will also want to combine it with additional context (what happened there before ? is there a known source (star, galaxy, AGN etc) nearby?) so the a competition was run to select teams who are building Alert Brokers for the community.</p>
<p>These alert brokers are where scientists and other interested users will go to get the alerts, rather than getting them directly from Rubin itself. The brokers will ingest the stream of alerts, combine it with other known information, cross match with other catalogs and allow users to define &quot;filters&quot; to pick out objects that interest them e.g. &quot;find me new alerts that occur within 5&quot; of a known galaxy, have a blueish color and have increased in brightness by more than 0.5mag in the last day&quot;. Alerts and objects that pass these filters (or website queries) will be sent to or requested by users to perform the science (e.g. discover new young supernovae, find new asteroids in the outer solar system) or to do follow-up with other telescopes.</p>

CC BY-SA 4.0
2024-08-01T20:41:25.537Z
In related news: Rubin's 3.5 meter secondary mirror (M2) was installed into the telescope today, see [press release](https://rubinobservatory.org/news/secondary-mirror-installed)
astrosnapper
CC BY-SA 4.0
2024-08-03T13:00:59.157Z
Thank you! The performance schedule on their site is two months out of date. I'm trying to keep track of when we'll actually get to see something, and I guess it'll be early next year. And we can't get anymore specific info than that.
Miss Understands
CC BY-SA 4.0
2024-08-03T17:19:23.247Z
The [Rubin Community Workshop](https://project.lsst.org/meetings/rubin-2024/) was July 22-26 and updated schedule is likely in the [Plenary Status Update](https://youtu.be/CUuxikD0p-U) (I couldn't go to this years meeting but schedule updates have always been in this update at previous meetings). I expect the main Rubin website will get an updated schedule in due course; these sort of things need to be approved by the NSF and DOE and other partners
astrosnapper
CC BY-SA 4.0
2024-08-01T00:20:13.717Z
2024-08-01T15:45:54.957Z
2024-08-01T15:45:54.957Z
astrosnapper
<p>I'm talking about the Vera wide field telescope that surveys the entire sky every night. It's coming online next year.</p>
<p>I heard there are supposed to be 1,000 events per night, asteroids and stuff. Is there a website somewhere you can go to check boxes for what types of events you'd like to be alerted about?</p>
<p>I assume it's an email list, right?</p>
<p>Can anybody sign up, or just scientists?</p>

CC BY-SA 4.0
2024-08-04T04:37:23.687Z
different questions but related and potentially helpful answers: [Is there a standardized "Astronomical Alert" system?](https://astronomy.stackexchange.com/q/32778/7982) and [Automated (and hopefully free) systems I can subscribe to sending email or SMS text message when the T Coronae Borealis Nova becomes visible?](https://astronomy.stackexchange.com/q/57236/7982) and [Will the Vera C. Rubin Observatory (formerly the LSST) make a significant increase in the rate of astronomical event alerts?](https://astronomy.stackexchange.com/q/32777/7982)
uhoh
<vera-c-rubin-observatory>
How do you get on the list to be notified of realtime LSST alerts (like supernovae)?
Miss Understands
# How do you get on the list to be notified of realtime LSST alerts (like supernovae)?

(Asked by: username_0 on 2024-07-31)

I'm talking about the Vera wide field telescope that surveys the entire sky every night. It's coming online next year.

I heard there are supposed to be 1,000 events per night, asteroids and stuff. Is there a website somewhere you can go to check boxes for what types of events you'd like to be alerted about?

I assume it's an email list, right?

Can anybody sign up, or just scientists?

**Tags:** vera-c-rubin-observatory

> **Comments:**
> **username_1**: different questions but related and potentially helpful answers: [Is there a standardized "Astronomical Alert" system?](https://astronomy.stackexchange.com/q/32778/7982) and [Automated (and hopefully free) systems I can subscribe to sending email or SMS text message when the T Coronae Borealis Nova becomes visible?](https://astronomy.stackexchange.com/q/57236/7982) and [Will the Vera C. Rubin Observatory (formerly the LSST) make a significant increase in the rate of astronomical event alerts?](https://astronomy.stackexchange.com/q/32777/7982)  

---

## 1 answers

### Answer by username_2 on 2024-08-01. Score: 22 | Accepted answer

TLDR: The alerts from the Vera C. Rubin Observatory will be public to everyone but the alert rate and packet size are too large to distribute by email and will be distributed through alert brokers.

The [Rubin Observatory](https://www.lsst.org/) will indeed carry out a survey of the visible sky every night from it's location on a mountaintop in Chile. However the number of alerts and the amount of information needed to be transmitted per alert in order to understand the source that produced the alert and do science on it is much too large to be simply sent out to whoever is interested and will instead flow through a series of 7 [Alert Brokers](https://www.lsst.org/scientists/alert-brokers) that will ingest the (compressed binary) alert packets and serve them to users.

Rubin, during the course of it's Legacy Survey of Space and Time (LSST) operates by repeatedly surveying pre-defined patches of sky. This is called a *visit* and will consist of either 2x15s or 1x30s exposures (TBD based on camera performance and amount of satellite constellations). These visits occur every approx. 42s to somewhere on the sky with the same patch of sky revisited ~40 minutes later (to find/eliminate moving asteroids). The 2x15s exposures are combined together and differenced with a previously constructed deeper reference image of the same patch of sky combined from multiple exposures. Everything that is different (changed in brightness or position) between the new image and the reference that passes certain cuts, gets sent out as an alert packet. The aim is for all of this processing to occur 60s after shutter close.

Estimates of the [number of alerts](https://dmtn-102.lsst.io/) are uncertain (since no surveys to LSST's depth have been performed) and vary *a lot* depending on the galactic latitude and stellar density. The range spans from the approximately 1000 the OP quotes (*Note* this 1000 is per-*visit*, not per night) to ~40,000 alerts per visit. Depending on how well the actual finished telescope performs, the expectation is ~900 visits per night. This means between 0.9 and 36 *million* alerts per night. Each alert packet contains a [lot of details](http://ls.st/dpdd) (see Section 3.5) on position, shape, brightness, errors, postage stamps etc and is ~82kB in size. This stream is too large to give to everyone who wants it and you will also want to combine it with additional context (what happened there before ? is there a known source (star, galaxy, AGN etc) nearby?) so the a competition was run to select teams who are building Alert Brokers for the community.

These alert brokers are where scientists and other interested users will go to get the alerts, rather than getting them directly from Rubin itself. The brokers will ingest the stream of alerts, combine it with other known information, cross match with other catalogs and allow users to define "filters" to pick out objects that interest them e.g. "find me new alerts that occur within 5" of a known galaxy, have a blueish color and have increased in brightness by more than 0.5mag in the last day". Alerts and objects that pass these filters (or website queries) will be sent to or requested by users to perform the science (e.g. discover new young supernovae, find new asteroids in the outer solar system) or to do follow-up with other telescopes.

> **Comments:**
> **username_2**: In related news: Rubin's 3.5 meter secondary mirror (M2) was installed into the telescope today, see [press release](https://rubinobservatory.org/news/secondary-mirror-installed)  
> **username_0**: Thank you! The performance schedule on their site is two months out of date. I'm trying to keep track of when we'll actually get to see something, and I guess it'll be early next year. And we can't get anymore specific info than that.  
> **username_2**: The [Rubin Community Workshop](https://project.lsst.org/meetings/rubin-2024/) was July 22-26 and updated schedule is likely in the [Plenary Status Update](https://youtu.be/CUuxikD0p-U) (I couldn't go to this years meeting but schedule updates have always been in this update at previous meetings). I expect the main Rubin website will get an updated schedule in due course; these sort of things need to be approved by the NSF and DOE and other partners  

---

