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"28072 results found.
- Swift-BAT trigger 107873: No Swift XRT counterpart
- GRB 050309, Early optical limits from RAPTOR
- Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
- GRB 050309 : Lulin R-band observation
- Swift 107873: P60 Optical Observations
- GRB 050306: CORRECTION to date of observation
- GRB 050306: No Swift UVOT Optical Counterpart Detected
- Swift trigger 107518: optical observation
- GRB 050306,optical observation
- Ongoing activity of SGR 1806-20 after the giant flare
- GRB 050219b: candidate NIR afterglow
- GRB050223: No Swift UVOT Detection of Afterglow Emission
- GRB050223: ROTSE-III Optical Observations
- GRB050219b: CORRECTION to time of UVOT observations
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB050219b: No Swift UVOT Detection of Afterglow Emission
- GRB050219a: No Swift UVOT Detection of Afterglow Emission
- GRB050215b: Swift UVOT Detection of Afterglow Emission
- GRB050215b: No Swift UVOT Detection of Afterglow Emission
- GRB050215a: No Swift UVOT Detection of Afterglow Emission
- Swift-BAT detects two bursts: GRB050215a and GRB050215b
- GRB 050215b, BOOTES-1B optical limit
- GRB050215B: ROTSE-III optical observations
- GRB050215A: ROTSE-III Optical Observations
- GRB050209: REM optical observations
- GRB 050209 Optical observations
- GRB050209: P60 Optical Observations
- GRB 050209: Optical observation
- GRB050128,optical observations
- GRB 050124 I-band observation
- GRB050124,optical observation
- GRB050124: Refined BAT position, spectral and fluence information
- GRB050123,optical observation
- GRB 050123: KAIT observations
- GRB 050123(=H3666): A GRB Localized in Real Time by HETE
- GRB 050117, I-band observations
- The giant outburst from SGR 1806-20
- Swift-BAT Time History of GRB041219
- GRB041220: Swift-BAT burst
- Deep RAPTOR observations during GRB 041219
- GRB041219c: Third Burst in One Day from Swift-BAT
- GRB 041219 ,optical observation
- GRB 041218: R-band optical observations
- Swift-BAT detection of the bright long burst GRB041219
- GRB041219: Prompt Optical Observations from ROTSE-IIIb
- GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
- GRB041211: RAPTOR observations
- GRB041211, BVRcIc field calibration
- GRB041211,optical observation
- GRB 041211: KAIT observations
- Distribution of IBAS Alerts for NON-GRB sources
- GRB 041006: GETS Optical Afterglow Observation
- Summary of the recent bursts from SGR 1806-20
- GRB041015, optical observation in CrAO
- Bright bursts from SGR1806-20
- GRB 041016: BOOTES-2 simultaneous observation
- GRB041016,optical observation
- GRB 041016: Optical limits
- GRB 041016:Optical limit during first minute
- GRB041016: MASTER: Optical observations
- GRB041006: Near Infrared observations
- GRB 041016: Optical limit
- GRB 041015 R band observations
- GRB040924, BVRcIc field calibration
- GRB041015: MASTER: Optical observations
- GRB041015,optical observation
- GRB041006: MASTER optical observations
- GRB041006,optical observation
- GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
- Konus-Wind observation of a series SGR 1806-20 bursts on 041005
- GRB040929,optical observation
- GRB040924,optical observation
- GRB040924: KAIT observations
- GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
- GRB040924 (H3564): Optical afterglow candidate
- XRF040912, BVRcIc field calibration
- XRF040916, BVRcIc field calibration
- GRB040916: Optical observations
- GRB/XRF040912,optical observations
- GRB 040912, BVRI observations
- Optical observations of field of GRB040912
- HETE 3557: Optical observations
- GRB040825B, BVRcIc field photometry
- GRB040825A, BVRcIc field photometry
- GCN GRB OBSERBATION REPORT
- GRB 040825A,optical observations
- Increase of SGR 1806-20 activity
- GRB040825A: optical observations
- GRB040825B: optical observations
- GRB040825B (=H3510): An XRF Localized in Real Time by HETE
- GRB 040825A: Optical observations.
- MASTER: GRB040825b optical observation
- GRB040825B: Correction to GCN 2657
- GRB 040812: Second epoch CXO Observations
- GRB040823,optical observation
- Triangulation of GRB 040816 (Konus-Wind - Helicon-Coronas-F)
- CXO observation of GRB 040812
- Ongoing activity of SGR 1806-20
- GRB040709 J,H-band observations
- GRB040706:observation at University of Miyazaki