SWIFT still not fully "repaired", good time to discover GRB afterglows from Earth

Affiliation
American Association of Variable Star Observers (AAVSO)
Sat, 02/26/2022 - 23:56

After suffering the loss of a reaction wheel, the SWIFT satellite was abe to partially resume it's science mission on Feb 17th, but it seems it is still not fully capable to swiftly (forgive me the pun) slew automatically to observe optical Gamma Ray Burst *afterglows*, this leaves an interesting opportunity for us terrestrial observers.

As I explained in my recent AAVSO webinar [2], the SWIFT satellite detects gamma ray bursts with a fairly precise sky localization if the burst is inside the FOV of it's gamma ray telescope. What it would then usually do (fully automatically) is to slew the spacecraft to bring the sky position of the GRB into the narrower FOV of the X-ray and UV/optical telescopes co-mouted on the spacecraft, with the intention to image any X-ray and/or optical afterglows. However, according to NASA [1]:

"On 17 February 2022, Swift resumed pointed observations of pre-planned science targets. Autonomous slews in response to on-board GRB triggers remain disabled for the time being"

So amateur observers can help out! With Smart Phone Apps like "Astro Colibri" [3] or with a few lines of Python code , you can receive messages from the SWIFT satellite within seconds after a GRB was detected. And if you happen to be observing anyway, why not quickly take this as a target of opportunity and go hunting for the optical aferglow?

Good luck!

HBE

[1] https://swift.gsfc.nasa.gov/

[2] https://youtu.be/bQfXWKMjWkc

[3]  https://astro-colibri.herokuapp.com/home

Affiliation
American Association of Variable Star Observers (AAVSO)
...and SWIFT is back in full…

...and SWIFT is back in full service ,  slewing to GRBs like before the problem with a reaction wheel.

If fact I'm just now practicing GRB hunting by ponting to GRB 220306B (no optical afterglow expected tho) and try to catch photons in between clouds.

More on that perhaps later

HB

Affiliation
American Association of Variable Star Observers (AAVSO)
VOEvent handler

Has there been any thought given recently to handling these events thru a VOEvent handler?

https://voevent.readthedocs.io/en/latest/intro.html

I remember that during Arne Henden's time as Director a VOEvent handler was developed at Hq and used successfully by a few observers. The handler still exists somewhere.  Bob Denny had developed an interrupt handler for ACP/Scheduler that would receive and respond to these events during an observing run.    People getting out of bed in the middle of the night was not expected!  It seems that several such processes like SWIFT and SNEWS would benefit from this type of approach and much of the work is already done.

 

Bill Goff

Affiliation
American Association of Variable Star Observers (AAVSO)
Interesting idea

What exactly would you need, tho? The messages that SWIFT and FERMI broadcast over public GCN are actually already VOEvent messages, so if someone still has that ACP code that reacts to incoming VOEvent messages in an intelligent way, that would be great to re-distribute to the wider community. Observers could then listen for events from GCN and react to it in their local observatories.

 

Cheers

HB

Affiliation
American Association of Variable Star Observers (AAVSO)
VOEvent handler

I had hoped some of the folks involved in the original project would jump in to add a few pieces of info.  Hq staff had built a VOevent piece that notified our users of observable events.  Many of the events are not observable, wrong hemisphere, etc. The Hq piece is probably still around but it may take some effort to put it back in place.  I'm not sure how that would fit in these days.

Bill

Affiliation
American Association of Variable Star Observers (AAVSO)
REFITT Project

There is a project called REFITT  

http://refitt.org/

that might be of interest: The idea is similar to what you descibe: A central broker will (soon, I was told) be generating VOEvent messages targetted specifically for registered observers based on their observatory capabilities, which can then be used with an ACP Scheduler for ToO observations by robotic scopes. Probably worth exploring.

Cheers

HB

 

Affiliation
American Association of Variable Star Observers (AAVSO)
REFITT project

Hello,

Thanks, yes this is very similar.  As I understand it, AAVSO was building a broker piece like you describe.  I'll take a look and see if this is an approach I can participate in.

 

Bill Goff