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"5401 results found.
- GRB 080727B: KAIT photometry and an early lightcurve break
- Trigger 317205: Swift detection of an outburst from XTE J1701-407
- GRB 080603A: CrAO optical observations
- Refined analysis of Swift Trigger 316063, is IGR J08408-4503
- Trigger 316063: Swift detection of a transient
- GRB 080701A, VATT optical upper limit
- GRB 080701A: Early Super-LOTIS Observations
- GRB 0800603A: optical observation
- GRB 080603B: TLS Afterglow Observation
- GRB 080603B : Liverpool Telescope Observations
- GRB 080603B: Swift-XRT refined analysis
- GRB 080603B: Swift/UVOT detection of the afterglow
- GRB 080603B, Swift-BAT refined analysis
- GRB080603B: RTT150 optical observations, break in light curves
- GRB 080603B: Swift detection of a burst with optical afterglow
- GRB 080603B: ROTSE-III Detection of Optical Counterpart
- SGR 1627-41: Chandra/RXTE/Swift Observations Scheduled
- GRB 080503: 2nd Epoch Chandra X-ray Observations
- GRB 080523, Swift-BAT refined analysis
- GRB 080523: Swift detection of a burst
- GRB080521(?): detection of possible burst from BAT slew data and XRT ToO
- GRB 080514B, GROND observations
- GRB 080506: NAYUTA Optical Observation
- GRB 080507: Keck photometry
- GRB 080503: MITSuME Ishigakijima optical upper limits
- GRB 080503: MITSuME Akeno optical upper limits
- GRB 080503: New candidate afterglow/host in Gemini imaging
- GRB960202B - on the association with SN 1996cr
- Possible GRB 080315: XRT non-detection of afterglow
- GRB 080413A: MOA-II optical afterglow observations
- GRB080330: MAGIC telescope GeV observation
- GRB 080330: RAPTOR detection of prompt optical flash
- GRB 080405: Swift-XRT position
- GRB 080330: REM optical observations
- GRB 080330, SMARTS optical/IR afterglow observations
- GRB 080330 Swift-UVOT refined analysis
- GRB 080328: Suzaku WAM observation of the prompt emission
- Konus-Wind observation of GRB 080328
- GRB 080330: GROND Observations
- GRB 080330: TAROT Calern observatory optical observations
- GRB 080330A: PAIRITEL Infrared Detections
- GRB 080330A: ROTSE-III Detection of Optical Counterpart
- GRB 080330: Swift detection of a burst with an optical counterpart
- GRB 080328: Swift detection of a burst with an optical counterpart
- GRB 080319C: UVOT Observations
- GRB 080319B: Gemini-South photometry
- GRB 080319A/B/C: INTEGRAL SPI-ACS light curves available
- GRB 080319b light curve by Pi-of-the-Sky
- GRB 080319b: Early IR Imaging from PAIRITEL
- Swift Trigger 306745 is not a GRB
- GRB 080315: TAROT Calern observatory optical observations
- GRB 080310: ROTSE-III Observations of Optical Counterpart
- GRB080310: Optical observation by MITSuME telescope
- GRB 080310: PAIRITEL detection and PAIRITEL+KAIT+UVOT SED
- GRB 080310: Swift-XRT refined analysis
- GRB 080310: RRM optical photometry with the VLT
- GRB080310: Super-LOTIS suggestion of brightening
- GRB 080310, SMARTS optical/IR afterglow observations
- GRB080229, optical upper limit (Correction)
- GRB080229, optical upper limit
- GRB 080307: Early RAPTOR Limits
- GRB080307: Optical upper limits
- GRB 080303: REM NIR afterglow candidate
- ESO optical and NIR observations of GRB 080218B
- GRB 080218b, SMARTS optical/IR limits
- GRB 080121: Upper limit on X-ray afterglow
- GRB 071227: optical afterglow
- GRB 071227: Magellan observations
- GRB071227: Swift/UVOT refined analysis
- GRB 071129: Swift detection of a burst
- GRB 071122: Swift detection of a burst
- GRB071118 MITSuME OAO optical observation
- GRB071109: Super-LOTIS observations
- GRB071010b: optical observation
- GRB0711101: Two new source from Xinglong TNT observation
- GRB 071101: a nearby galaxy
- GRB 071031: Swift-XRT Team refined analysis
- GRB 071031: GROND detection in all bands
- GRB 071031: Swift detection of a burst with an optical counterpart
- GRB 071025: Kuiper Telescope Optical Observations
- GRB071021: MITSuME Okayama Optical Upper Limits
- GRB 071020: Swift-XRT refined analysis
- GRB 071020: Swift detection of a bright burst
- GRB 071013: TNT optical data refined analysis
- GRB 071010B correction to GCN 6892 optical observations
- GRB 071010B optical photometry
- GRB 071011: Optical afterglow candidate
- GRB 071010 REM NIR observations
- GRB 071010: Swift detection of a burst
- Recent SGR1806-20 Activity
- GRB 070923: Swift detection of a short hard burst
- GRB920925C: search for host galaxy
- Candidate Orphan GRB Optical Transient in IC 4779
- GRB 070810A: ROTSE-III Refined Analysis
- Swift trigger on 4U 1700-377 while star tracker loss-of-lock
- GRB 070729: Swift-XRT refined analysis
- GRB 070729: Magellan NIR Observations
- GRB 070729: Swift detection of a short hard burst
- GRB 070724B: Swift-XRT afterglow likely candidate
- GRB 070724B: Swift-XRT afterglow candidates