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"- GRB 131229A: Fermi GBM detection
- GRB 131231A: P60 observations
- GRB 131227A: KAIT light curve analysis
- GRB 131231A: Swift-XRT observations
- GRB 131231A : xinglong TNT optical observation
- GRB 131231A: MDM afterglow observation
- GRB 131231A: VLT/X-shooter redshift
- GRB 131231A: Fermi GBM detection
- GRB 131231A: iPTF optical afterglow candidate coincident with Nanshan detection
- GRB 131231A: afterglow confirmation from the NOT
- GRB 131231A: Nanshan afterglow candidate
- GRB 131231A: Fermi-LAT detection of a burst
- Konus-Wind observation of GRB 131229A
- GRB 131229A: CARMA 3mm observations
- GRB 131229A: Magellan upper limit
- GRB 131229A: GROND observations
- GRB 131229A: Swift-BAT refined analysis
- GRB 131229A: Swift-XRT refined Analysis
- GRB 131229A: Swift/UVOT Upper Limits
- GRB 131227A: GROND Upper Limits
- GRB 131229A: Enhanced Swift-XRT position
- GRB 131229A: Deep Gemini-South Imaging
- GRB 131229A: KAIT Optical Upper Limit
- GRB 131229A: P60 nondetection
- GRB 131229A: Swift detection of a burst
- GRB 131224A: 5.8 GHz VLA observations
- GRB 131227A: P60 Limits
- GRB 131227A: Gemini-North Redshift
- GRB 131227A: Swift-XRT refined Analysis
- GRB 131227A: Xinglong optical observations
- GRB 131227A: Swift/UVOT Upper Limits
- GRB 131227A: Swift-BAT refined analysis
- Konus-Wind observation of GRB 131226A
- GRB 131227A: Enhanced Swift-XRT position
- GRB 131227A: OT candidate from KAIT Optical observations
- GRB 131227A: Swift detection of a burst
- GRB 131224A: Swift/UVOT Upper Limits
- GRB 131225A: MASTER-Net optical observations
- GRB 131226A, Swift-BAT refined analysis
- GRB 131226A: Swift detection of a burst
- GRB 131216A: Suzaku WAM observation of the prompt emission
- GRB 131224A: Swift-XRT observation
- GRB 131225A: MAXI/GSC detection
- GRB 131224A: MASTER-Net early optical observations
- GRB 131224A: A short GRB detected by INTEGRAL
- GRB 131218A: GROND Upper Limits
- GRB 131218A: Swift XRT and UVOT observations
- Fermi Gamma-ray Burst Monitor trigger 409187680/131219968 is not a GRB
- GRB 131218A: Zadko observatory - Gingin optical candidate
- GRB 131218A: TAROT La Silla observatory optical observations
- GRB 131218A: a long GRB detected with INTEGRAL
- IPN Triangulation of GRB 131216A
- GRB 131216A: Fermi GBM observation
- GRB 131216A: Fermi-LAT detection of a burst
- GRB 131215A: MAXI/GSC detection
- Trigger 581129: Swift-BAT triggered on noise
- GRB 131205A: GROND confirmation of afterglow
- INTEGRAL Weak trigger #6403: AROMA-N Optical Observation
- GRB 131209A: Swift XRT and UVOT observations
- GRB 131209A: Fermi GBM observation
- GRB 131209A Tiled Swift observations
- Konus-Wind observation of GRB 131209A
- IPN Triangulation of GRB 131209A
- GRB 131209A: Fermi-LAT detection of a burst
- GRB131202A : GROND observations
- GRB131205A : GROND Observations
- GRB 131205A: Swift-BAT refined analysis
- GRB 131205A: Swift-XRT refined Analysis
- Swift Trigger 580319 is not a GRB
- GRB 131205A: Swift/UVOT Upper Limits
- GRB 131205A: Enhanced Swift-XRT position
- GRB 131205A: Zadko observatory - Gingin optical observations
- GRB 131205A: Swift detection of a burst
- GRB 131127B: Bassano Bresciano Observatory,archival confirmation of iPTF13ecv
- GRB 131202A: theoretical estimation of the redshift
- GRB 131127B: archival confirmation of iPTF13ecv as a CV
- GRB 131127B: rejection of optical counterpart candidates
- GRB 131126A: Fermi GBM observation
- GRB 131126A: iPTF upper limits on the afterglow of a short GRB
- GRB 090530: X-shooter redshift
- GRB 131127A: optically dark burst
- GRB 131202A, Swift-BAT refined analysis
- GRB 131202A: Swift/UVOT Upper Limits
- GRB 131202A: Swift-XRT refined Analysis
- GRB 131202A: RATIR Optical and NIR Observations
- GRB 131202A: Fermi GBM Detection
- GRB 131202A: Enhanced Swift-XRT position
- GRB 131202A: Bassano Bresciano Observatory optical upper limit
- GRB 131202A: Tautenburg observations
- GRB 131202A : XMM-Newton planned observation
- GRB 060614: theoretical derivation of the redshift and need for deeper search of the host galaxy
- GRB 131202A: Swift detection of a burst
- GRB 131127B: Bassano Bresciano Observatory optical observations of iPTF13ecv
- GRB 131122A: Swift-XRT Further Observation
- GRB 131128A: Bassano Bresciano Observatory optical upper limit
- GRB 131127A: RATIR Rejection of High-z Candidate
- GRB 131128A; Fermi GBM observation
- GRB 131125A: MASTER-Net very early optical observations
- GRB 131125A: iPTF upper limits on the afterglow of a short GRB
- Konus-Wind observation of GRB 131126A