Affiliation
American Association of Variable Star Observers (AAVSO)
Thu, 06/24/2021 - 11:07

Hello all!

I observed optical afterglow of gamma-ray burst GRB 210619B using remote telescopes.

Long-duration GRB 210619B was detected by the Swift Burst Alert Telescope at 23:59:25 UT on June 19, 2021. The peak count rate was ~100,000 counts/sec (15-350 keV); for comparison: the peak count rate of the recent GRB 210610B was ~11,000 counts/sec (15-350 keV). Redshift of 1.937 was reported in the GCN circular #30272 https://gcn.gsfc.nasa.gov/gcn3/30272.gcn3 with information: "GRB 210619B will likely be among the most energetic GRBs" and "the initial prompt emission spike is extremely luminous, and we expect the afterglow to be among the most luminous prompt flashes ever detected".

On June 20, 2021, I observed it with telescope T18 (0.32-m f/8.0 reflector + CCD) of iTelescope.Net, 0.974 days after the trigger. Magnitude = 20.5 +/- 0.4. More informatiom was published in the GCN circular #30292 https://gcn.gsfc.nasa.gov/gcn3/30292.gcn3  Stacked image available here: https://www.flickr.com/photos/filipp-romanov/51261591951  

On June 21, 2021, I observed it with 0.355-m f/6.2 Schmidt-Cassegrain telescope of Abbey Ridge Observatory, 1.155 days after the trigger. Magnitude = 20.0 +/- 0.2. More informatiom was published in the GCN circular #30305 https://gcn.gsfc.nasa.gov/gcn3/30305.gcn3 Stacked image available here: http://www.abbeyridgeobservatory.ca/images/GRB210619B.jpg

With best regards, Filipp.

Affiliation
American Association of Variable Star Observers (AAVSO)
Nice!!!!

Here's an idea …

Nice!!!!

Here's an idea (please comment on what you think about it):

GRB afterglow observations are somewhat different from other "variable star" observations that go into the AAVSO database. I wonder whether the AAVSO should provide a centralized spot where our observers can upload images (in FITS format for scientific consumption) and other relevant information e.g. pointers to GCNs. That would give more visibility and would serve as a long-term archive that is easier to navigate than looking for past events in this forum. 

I was thinking about the AAVSO github perhaps.

 

Would that be useful? If so I can propose this during the next section leader meeting.Let me know.

CS

HB 

 

Affiliation
American Association of Variable Star Observers (AAVSO)
About your idea

Hello!

Regarding images (of any format, fits or jpg) - this is really necessary for such researches. I have to upload images to Flickr, but it’s not at all like upload it on the AAVSO website. And this is interesting idea about the special observations archive.

With best regards, Filipp.

Affiliation
American Association of Variable Star Observers (AAVSO)
tracking/tagging GRB and other HEN observations

Interesting ideas.

Would adding a searchable tag to the observation be of help? Add to the submission notes field TargetType=GRB
    Would need to add to the search function the ability to look for this tag.

Do all GRB's end up in VSX? VSX has a tagging mechanism so that you could generate lists.

Why are images necessary for this kind of research?

George

 

Affiliation
American Association of Variable Star Observers (AAVSO)
GRBs and VSX

I don't think that currently GRBs end up in VSX often. Anyway, they evolve so quickly that you want to share your observation (e.g. in a GCN circular, complete with pictures etc) immediately, before staff at the AAVSO would typically have a chance to make an entry into VSX or prepare a sequence etc.

Photometry of those faint events can be tricky and might need image subtraction techniques or analysis of the PSF, so it's never wrong to provide your images so others can use more elaborate methods than the GRB-afterglow-hunter him/her self.

It's also a good quality check, because remember this is difficult stuff and as amateurs we might need to convince pros that we actually captured the GRB and didn't just mess up and measured a cosmic ray hit or hotpixels :-)   ,. We are happy to get even one observation by a single observer, it's kind of rare to have multiple observers per event confirming each others measurements.

CS

HB

 

Affiliation
American Association of Variable Star Observers (AAVSO)
FTP site for GRB's?

In the past GRB images were ftp'd to the AAVSO.
 

FTP is an old tech with security issues, so there is not a lot of enthusiasm to do this again... Unless there was a proposal to make the case that there is indeed renewed interest in tracking and sharing GRB images.

George

 

Affiliation
American Association of Variable Star Observers (AAVSO)
FTP is so 80s

Indeed, we should not go back to FTP. 

I think Github would be a worthy successor to an FTP served filespace. There is renewed interest in sharing GRB afterglow images, so let's use something modern.

Cheers

HB