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').
10041 results found.
- XRF030723 (=H2777): Second Epoch Magellan Observations
- IPN triangulation of GRB030726 (large error box)
- XRF 030723: confirmation of fading optical counterpart
- XRF030723(=H2777): Chandra Observations
- Magellan Observations of XRF030723 (=H2777)
- GRB030723: Upper limits from historical observations
- GRB030725, possible optical transient
- GRB030725 (=H2779): A Bright GRB Localized by HETE
- XRF030723 (= H2777): Chandra Observations Scheduled
- XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
- H2768, H2770, and H2771: Three Bursts from SGR1806-20
- GRB030329: RTT150 optical observations
- IPN detection of renewed activity from SGR1806-20
- HETE detection of burst from SGR1806-20
- GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
- GRB 030528: Optical Observations
- GRB030528(=H2724): Observations with the Chandra X-ray Observatory
- GRB030528: Chandra TOO Planned
- GRB030528(=H2724): Revised SXC Localization
- GRB 030329: optical observations
- GRB030528 (H2724): A long GRB localized by HETE
- GRB 030329: HST ACS Observations of the Host
- GRB 030329 Optical Observations
- GRB030324: Further Observations of the Candidate Optical Afterglow
- GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
- IPN triangulation of GRB030519B=H2716 (small error box)
- GRB 030418: Second Epoch Optical Observations with Magellan
- GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
- IPN triangulation of GRB030519 (annulus)
- IPN triangulation of GRB030518A (annulus)
- GRB030329: RTT150 optical observations
- GRB 030329: Optical limit (contemporaneous photography)
- GRB030429: RTT150 optical obs., correction to GCN 2208
- GRB 030329: High-Resolution Spectroscopy of the Host
- GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
- GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
- XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
- GRB030429: RTT150 optical observations, a possible host galaxy
- GRB030329: RTT150 optical observations and upper limit for a host
- GRB030329: RTT150 optical observations and upper limit for a host
- GRB 030429: IR photometry with IRSF/SIRIUS
- GRB 030329, the review of the sky area in plate archive (1950-1998)
- Optical Observations of GRB 030418 with Magellan
- GRB 030329: optical spectropolarimetry at VLT
- GRB030329: 444 AAVSO Measurements
- GRB030418: Upper limits from recent and historical observations.
- GRB 030418: Optical afterglow candidate
- GRB030329: VR Photometry at TNG
- GRB030324: Candidate Optical Afterglow
- GRB 030413: Optical Observations
- IPN triangulation of GRB030413 (small error box)
- IPN triangulation of GRB050403 (small error box)
- IPN triangulation of GRB030403 (annulus)
- GRB 030329: BVRI photometry at Asiago
- GRB 030329: VLT V-band photometry
- GRB 030329: Supernova Confirmed
- GRB030329: RTT150 optical observations
- GRB030329: RTT150 optical observations
- GRB 030329: Supernova Spectrum Emerging
- GRB030329: RTT150 optical observation
- GRB 030329, Optical observations
- GRB030329: final R-band light curve by MASTER
- GRB030329 Radio 23/43/90 GHz observations at Nobeyama
- GRB030329: optical observations at Tokyo Tech
- GRB 030329: optical observations
- GRB030328: Full Observation, X-ray Fading and Spectrum Measured
- GRB030329: Optical observations at Teramo
- GRB 030329: beginning of the new fading phase in optical band
- GRB 030329, optical spectroscopy
- GRB 030329: optical photometry
- GRB 030329: further optical observations
- GRB030329: R and B observations
- GRB030328: X-ray Fading and Spectrum Measured with Chandra
- GRB 030329: Light curve observed during the change of its slope.
- GRB 030329: Optical Decay
- GRB030329: optical spectroscopy with the TNG
- GRB030328: X-ray Afterglow Observed with Chandra
- GRB 030329: optical observations
- GRB030329: Upper limits from recent and historical observations.
- GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
- GRB 030328: optical observations
- GRB030328: optical spectroscopy at TNG
- GRB030328: optical photometry at the TNG
- GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
- Re: GRB 030328: Finding chart
- GRB030324, optical observations
- GRB030323: Upper limits from recent and historical observations.
- GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
- GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
- GRB030324 (=H2641): A Long GRB Localized in Real Time by the HETE WXM
- GRB 030324, optical observations
- IPN triangulation of GRB030320B (annulus)
- GRB030226, addendum to GCN 1892
- IPN upper limit to a GRB associated with SN2003L
- IPN triangulation of GRB030317 (annulus)
- IPN triangulation of GRB030307 (annulus)
- GRB030226: Optical observations at Asiago
- GRB 030227: Optical observations
- IPN triangulation of GRB030301 (annulus)
- 030302: NOT A GRB