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"11074 results found.
- MASTER:optical observations probable GRB030414
- ROTSE-III prompt optical detections of GRB 030418
- GRB030329: VR Photometry at TNG
- IPN triangulation of GRB030413 (small error box)
- IPN triangulation of GRB030406 (small error box)
- GRB030329: BV photographic observations
- GRB030329: RTT150 optical observations
- GRB030329: Kiso B and R band observations
- GRB 030329: BV photographic observations
- GRB 030329, BVRI photometry
- GRB030329: final R-band light curve by MASTER
- GRB030329 - more 15 GHz radio data
- OT GRB light curves and SN predictions
- GRB 030329, BRI photometry
- GRB030328: Full Observation, X-ray Fading and Spectrum Measured
- Further AAVSO V,B,R observations of GRB030329
- GRB 030329: Additional Mt. Laguna Optical Observations
- GRB030329: further optical photometry and evidence for a light curve discontinuity
- GRB030329 - OT rebrightens
- AAVSO V & R observations of GRB030329
- GRB 030329: optical observations
- GRB030329 - Light curve flattening
- GRB030328: X-ray Fading and Spectrum Measured with Chandra
- GRB 030329: visual observations
- GRB030328: X-ray Afterglow Observed with Chandra
- GRB 030329, R-band observations, supplement
- GRB030329:optical observations by MASTER
- GRB030329 (=H2652): A Long, Extremely Bright GRB Localized by the HETE WXM and SXC
- RXTE detection of GRB 030329 afterglow
- GRB030328 (=H2650): A Long, Bright GRB Localized by the HETE WXM and SXC
- GRB 030328: Finding chart
- GRB 030328: Optical afterglow candidate
- GRB030324, optical observations
- GRB030324, Optical Observations
- GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
- GRB 030324, optical observations
- IPN triangulation of GRB030317 (annulus)
- GRB 030227: Optical limit at RIKEN
- IPN triangulation of GRB030306 (single small error box)
- IPN triangulation of GRB030306 (two small error boxes)
- IPN triangulation of GRB030306 (intense; annulus only so far)
- GRB030226: Analysis of Chandra data
- GRB 030227: fading of candidate optical afterglow 'S1-A'
- GRB 030227, possible optical counterpart of XMM-Newton source
- GRB030227 - faint tentative OT candidate
- GRB 030227: Kyoto optical observation
- GRB030227 localized by INTEGRAL
- GRB 030226, optical observations
- GRB 030226 Optical Spectra and R,I,z' Imaging
- GRB030226: Candidate optical afterglow
- GRB 030217: Optical Observations at 4, 5, and 6 Days
- GRB030217: optical observations
- GRB030131: Kiso optical limit for corrected position
- GRB030131: Optical limits for corrected position
- GRB 030131: afterglow candidate
- GRB030131: Optical limit
- GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
- GRB 030115, simultaneous observations by BOOTES-1
- GRB030115: R-band counterpart of IR candidate
- GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
- GRB030115 (=H2533): A Long GRB Localized by the HETE WXM and SXC
- GRB 030115, no optical candidate
- IPN triangulation of GRB030102B (portion of annulus)
- GRB on 20030101 seen by SPI-ACS
- GRB021219: a long GRB localized by INTEGRAL
- IPN detection of continued activity from SGR1806-20
- GRB 021201: Optical Observations
- GRB 021211: early break in light curve
- GRB021211: Optical observations in CrAO
- Chandra observation of the IPN error box of GRB021201 (short/hard)
- GRB 021211 Milagro GeV/TeV Observations
- GRB021211, OT at 108 s
- GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
- HETE 2493: Optical observations
- IPN triangulation of GRB021206 (exceptionally bright; annulus only)
- IPN detection of renewed activity from SGR1806-20
- GRB 021104, GRB 021112 and GRB 021113 - Milagro GeV/TeV Observations
- Improved IPN error box for GRB021125
- GRB021125 : A long GRB localized by INTEGRAL
- IPN confirmation of the reactivation of SGR1900+14
- IPN triangulation of GRB021119 (annulus)
- GRB021112: Optical Observations
- GRB021113 (=H2449): A Long GRB Localized by HETE
- GRB021112 (=H2448): A Long GRB Localized by HETE
- GRB 021023: Curious K-band Source(s) Just Outside of IPN Localization
- GRB 021004: optical observations
- IPN triangulation of GRB021020 (smaller error box)
- GRB021021(=XRF 021021): An X-ray Flash Localized by HETE
- IPN triangulation of GRB021020
- GRB 021016, optical observations
- GRB 021004: VRI observations at TNG: possible break
- GRB 021008, optical observations
- GRB021016(=H2397): A Long GRB Localized by HETE
- GRB021004: NIR and Optical observations
- GRB 021004: Optical measurement at OHP
- GRB 021004: optical spectroscopy
- GRB021004: BVRc photometry
- GRB 021004: Optical Photometry at 2.5 Days
- GRB 021004 radio observation
- GRB 021004: Optical Observations