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.
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
- GRB 060206: Tenagra II Observations
- GRB 060206: PROMPT Detections
- Retraction of orphan GRB afterglow candidate
- GRB060204a: Swift XRT Source is not GRB Afterglow
- GRB 060206: optical observations at Asiago
- Orphan GRB Afterglow candidate
- GRB 060204b: pseudo-z from spectral parameters of the prompt emission
- GRB 060206: Subaru/FOCAS optical spectroscopy
- GRB 060206: IR Detection of the Afterglow
- GRB 060206: Lick 3m Spectroscopy
- GRB 060204A: ROSAT Pointing
- GRB 060206: Super-LOTIS observations
- GRB060204A: Swift/UVOT observations
- GRB 060206: Swift-BAT refined analysis
- GRB 060206 : Lulin optical observations
- GRB060206: SDSS Pre-Burst Observations
- GRB060206: Swift XRT Refined Analysis
- GRB060206: Liverpool Telescope observation
- GRB 060206: Spectroscopic Redshift
- GRB060206: P60 Optical Observations
- GRB 060206: KAIT observations
- GRB060206: Swift XRT Position
- GRB060206: SARA Detection
- GRB 060206: RAPTOR observations of afterglow candidate variability.
- GRB 060206: High redshift burst
- GRB060204a: Swift XRT Detection of an Afterglow Candidate
- GRB060206 - Swift UVOT Confirmation of Optical Afterglow
- GRB060206: Optical afterglow
- GRB060206: Swift-BAT detection of a burst
- GRB 060204C: XRT analysis of Swift J061223.0+701243.9
- GRB060203: WHT Z-band observations
- BAT GRB 060204C is probably not a GRB
- GRB060204C: optical observation
- GRB 060204B: BVRi-band detections of optical afterglow
- GRB 060204A: Swift XRT upper limit
- GRB 060204A: FRAM optical observations
- GRB060204B: Swift/UVOT refined analysis
- GRB 060204C: optical observations
- Swift XRT Observation of GRB 060204C
- GRB 060204B: Swift-BAT refined analysis
- GRB 060204B: ART early limit
- GRB060204B: Swift XRT Team Refined Analysis
- GRB 060204C: OSN limits
- GRB 060204b: Keck/LRIS Afterglow Confirmation
- GRB 060204C: BOOTES-IR optical limits
- GRB 060204C: Liverpool Telescopes optical limit
- GRB 060204C: ROTSE-III Optical Limits
- GRB 060204C: Swift-BAT detection of a burst
- GRB 060124: Radio Observations
- GRB060204B: Faulkes OT candidate
- GRB 060204B: ART optical limit
- GRB 060204A: further INTEGRAL results
- GRB060204B, optical observation
- GRB060204B - SDSS pre-burst observations
- GRB 060203: Swift-BAT refined analysis
- GRB 060204B: Swift detection of a burst
- GRB 060204: a long GRB detected by INTEGRAL
- GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
- GRB 060203: RTT150 optical observations
- GRB060203: Swift XRT Team Refined Analysis
- GRB060203 - Swift UVOT observation
- Swift-BAT trigger is GRB 060203
- GRB 060203: IR Counterpart
- GRB060203: Observations with SARA
- GRB 060203: P60 Confirmation of Optical Afterglow
- Possible GRB 060203: candidate optical counterpart
- Swift BAT Trigger 180151: Swift XRT source detection
- Possible GRB 060203: optical observations at Asiago
- GRB 060202: PROMPT Observations
- Swift-BAT trigger 180151 is unknown origin at this time
- GRB 060202: GETS observation
- GRB 060202: Gemini-N J, H, K_s observations
- GRB 060202 : Kiso B and R band limit
- GRB 060202: Near-IR Observation with UKIRT/WFCAM
- GRB 060202: Optical Afterglow Candidate from Keck/LRIS
- GRB 060202: Refined analysis of the Swift-BAT burst
- GRB060202, optical observation
- GRB 060202: Swift/UVOT upper limits
- GRB 060202: Swift XRT Team Refined Analysis
- GRB 060202 : Lulin R and I band limit
- GRB060202: Faulkes North observation
- GRB 060202: Swift detection of a burst
- GRB 060121: Gemini Late-time Observations
- Erratum: SDSS pre-burst observations of GRB fields
- GRB 060130: PROMPT Observations
- GRB060130: Further R-band imaging
- GRB 060130: Swift/XRT observation
- GRB 051211A: MDM Observations
- GRB 060123: Gemini spectroscopy of the putative host galaxy
- GRB 060123: VLA Radio Observations
- GRB060130: Optical imaging
- GRB060130: REM infrared observations
- GRB 060130, SMARTS optical observations
- GRB 060130: FRAM optical observations
- GRB 060130: further INTEGRAL IBIS results
- GRB 060130: a long GRB detected with INTEGRAL
- Possible GRB 051221B: MDM Correction
- GRB050121: optical observation
- GRB050121b: optical observation
- GRB 060121: Confirmation of NIR Afterglow