GCN Circulars
GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.
Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search
To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.
Advanced Search Examples (click to copy):
subject:"Swift"body:"GRB"submitter:"Judith Racusin"20456 results found.
- GRB 120722A: Swift/UVOT Upper Limits
- GRB 120722A: VLT/X-shooter redshift of the host galaxy
- GRB 120722A: GROND detection of the afterglow
- GRB 120722A: 1.5m OSN I-band observations
- GRB 120722A: Xinglong TNT optical afterglow candidate
- GRB 120716A: EVLA Detection
- GRB 120716A: Swift-XRT detection
- GRB 120716A: Redshift confirmation from VLT/X-shooter
- VLT/FORS2 redshift of GRB120716A
- GRB 120716A: GROND confirmation of the optical/NIR afterglow
- GRB 120716A: Optical decay from NOT
- GRB 120716A: Candidate Optical Afterglow from PTF
- GRB 120711A: ATCA 34GHz final observations (upper limit)
- GRB 120714B: Swift/UVOT Detection
- GRB120714A: Swift/UVOT upper limits
- GRB 120714A: GROND upper limits
- GRB 120714B: GROND confirmation of fading afterglow
- GRB 120714B: Redshift from VLT/X-shooter
- GRB 120624B: VLA Observations
- GRB 120711A: INTEGRAL/SPI observations
- GRB 120714A: Swift-XRT observations
- GRB 120711A: ATCA 34GHz further observations (upper limit)
- GRB 120712A: Swift/UVOT Detection
- GRB 120712A: VLT/Xshooter redshift
- GRB 120712A Gemini-S redshift
- GRB 120712A: GROND Detection of the Optical/NIR Afterglow Candidate and photo-z
- GRB 120711A: ATCA 34GHz upper limit
- GRB 120711B: Swift/UVOT Upper Limits
- GRB 120711A: Swift/UVOT Observations
- GRB 120709A: Swift/UVOT Observations
- GRB 120711A: Swift-XRT observations
- GRB 120711A Gemini-S likely redshift
- GRB 120711A: GROND photometric redshift
- GRB 120711A: a possible X-ray transient
- Continued Skynet/PROMPT observations of GRB120711A
- GRB 120711A: ROTSE-III confirm of Optical Counterpart
- Skynet/PROMPT Observations of GRB120711A
- GRB 120709A: Swift-XRT observations
- GRB 120709A: optical afterglow limits
- GRB 120624B: mm detection at PdBI
- GRB 120703A: SMARTS optical/IR observations
- GRB 120703A: Swift/UVOT Detection
- GRB 120703A: NOT optical observation
- GRB 120701A: Swift/UVOT Detection
- GRB 120701A: GROND detection of the afterglow
- GRB 120630A: Swift-BAT/-XRT/-UVOT refined analysis
- GRB 120630A: NOT optical source within the XRT error circle
- GRB120624B: Chandra observations and afterglow detection
- GRB 120624B Further Swift-XRT analysis
- GRB 120624B: Swift/UVOT Upper Limits
- Watcher follow-up observations of IGR J17062-6143 (Swift trigger 525148)
- GRB 120624B: Further analysis of the HAWKI observations
- GRB 120624B: Swift-XRT observations
- GRB 120624B: GROND upper limits
- GRB 120624B: NIR counterpart candidate from HAWKI
- Skynet/PROMPT observations of IGR J17062-6143 (Swift trigger 525148)
- GRB 120624B: Discussion of Fermi and Swift measurements and future Swift observations
- GRB 120624B: NOT optical upper limit
- GRB 120624B: optical observations
- Swift Trigger 524949: Noise fluctuation near a galaxy
- GRB 120622A: MAXI/GSC detection
- GRB 120614A: MAXI/GSC detection of a burst
- GRB 120612A: optical observations
- GRB 120612A: Swift/UVOT observations
- GRB 120528C: MAXI/GSC detection
- GRB 120521C redshift estimate
- GRB 120528B: MAXI/GSC detection
- GRB 120521C: EVLA 22 GHz Detection
- GRB120521B: SSO 2.3m upper limits
- GRB 120521A: ATCA 34GHz upper limit
- GRB 120521C: Early Tautenburg limits
- GRB 120521A: GROND Upper limits
- GRB 120521C: Keck Observations
- GRB 120521C: Swift/UVOT Upper Limits
- GRB 120521B: Swift/UVOT Upper Limits
- GRB 120521B: GROND Upper limits
- GRB 120521C: PAIRITEL NIR Upper Limits
- GRB 120521C: BOOTES-1 optical observations
- GRB 120521C: WHT optical observations
- GRB120521C: Liverpool Telescope observations
- GRB 120521C: TAROT Calern observatory optical observations
- Swift starts a new program to find fainter transients
- GRB 120521A: Swift/UVOT Upper Limits
- Correction to GCN 13307 (GRB120521B)
- GRB120521B: Faulkes Telescope South observations
- GRB 120521B: TAROT La Silla observatory optical observations
- GRB 120521A: TAROT La Silla observatory optical observations
- GRB 120514A: Swift/UVOT Upper Limits
- GRB 120514A: UKIRT IR observations
- GRB 120514A: APEX observations of the submm counterpart
- GRB 120514A: TAROT Calern observatory optical observations
- GRB 120514A: Swift detection of a burst
- GRB 120422A: Konkoly optical observations
- Fermi Trigger 358364818: BOOTES-4 observations
- GRB 120510B/Fermi Trigger 358364818: MASTER possible OT candidate
- GRB 120510A: Swift XRT and UVOT observations
- GRB 120510A: MASTER follow up observations
- GRB 120510A: MAXI/GSC detection of a burst
- Fermi/GBM detection of a burst from the magnetar 1E 2259+5
- GRB 120422A: P200 NIR detection