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').
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"
3870 results found.
- GRB 030227: Kyoto optical observation
- GRB030227: refined INTEGRAL position
- GRB 030131: marginal optical detection
- Probable GRB030112 seen by SPI ACS
- VLT spectroscopy of the probable host of GRB 021211
- IPN triangulation of GRB021219
- IPN detection of continued activity from SGR1806-20
- IPN triangulation of GRB021211B (two large error boxes)
- GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
- IPN detection of renewed activity from SGR1806-20
- GRB 021201: BOOTES simultaneous optical observations
- GRB021004, late time optical observations
- IPN detection of continued SGR1900+14 activity
- IPN confirmation of the reactivation of SGR1900+14
- IPN detection of possible reactivation of SGR1900+14
- GRB 021113: Evidence for a Dark Optical Afterglow
- GRB 021112: RAPTOR Observations
- GRB021112 (=H2448): A Long GRB Localized by HETE
- IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
- SGR1900+14 activity, November 2-4, 2002
- Detection of activity from SGR 1900+14 with the RXTE/PCA
- IPN triangulation of a burst from SGR1900+14 on November 01, 2002
- IPN triangulation of a burst from SGR1900+14 on October 29 2002
- IPN triangulation of GRB021020 (smaller error box)
- IPN triangulation of GRB021020
- GRB021016(=H2397): A Long GRB Localized by HETE
- IPN triangulation of GRB021013 (two small error boxes)
- GRB021004: BVRc photometry
- GRB 021004: Optical Observations
- IPN triangulation of GRB020914
- IPN detection of a burst from SGR1900+14
- IPN triangulation of GRB020715 (=GRB150702)
- IPN triangulation of GRB150702
- IPN triangulation of GRB020708
- IPN triangulation of GRB020708
- Gemini IR Detection of AXP 1E 2259+586 Post-Burst
- SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
- AXP 1E2259+586: quasi-simultaneous optical observation
- AXP 1E2259+586 optical observations
- SGR-like Bursts from the AXP 1E 2259+586
- GRB 020604, optical observations
- GRB020604, optical observations
- IPN triangulation of GRB020604
- GRB020531: Optical observations
- GRB020525, optical observations
- IPN detection of possible bursts from SGR1806-20
- IPN triangulation of GRB020525
- XRF 020427: Sudden Ionospheric Disturbance (SID)
- Mars Odyssey joins the IPN
- Short RXTE/ASM transient 020406; may be a GRB
- XRF/GRB 011030: Detection of the Probable Host Galaxy
- IPN detection and localization of Cygnus X-1 flares
- RXTE Observations of SGR 1900+14
- SGR1900+14 activity
- IPN/HETE Detection of Bursts from SGR1900+14
- IPN Upper Limits to a GRB Associated With SN2002ap
- IPN detection of further activity from SGR1806-20
- Optical observation of SGR 1806-20 at the 6-m SAO telescope
- GRB010923 as seen by BeppoSAX GRBM
- HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
- Probable SGR or Short Duration GRB Detected by HETE
- Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
- GRB 010629 Optical Observations
- GRB010629: A Burst Localized by HETE
- Possible burst from SGR1806-20
- IPN detection of SGR1900+14
- X-ray precursors to the large flare from SGR 1900+14
- SGR 1900+14: No evidence of extended X-ray emission
- SGR 1900+14 : RXTE observations
- BeppoSAX/NFI Follow-up Observation of SGR 1900+14
- SGR1900+14
- SGR 1900+14: Correction to GCN 1049
- Millimeter observation of SGR 1900+14
- SGR 1900+14: Detection of extended X-ray emission
- Chandra Observations of SGR 1900+14
- SGR 1900+14, Chandra observations
- Chandra Observations of SGR 1900+14
- SGR1900+14, I-band observations
- GRB 980326: Late-time HST/STIS observations
- GRB 010214, I-band data
- GRB010214 Optical Observation
- GRB010126 optical observations
- Optical Observations of GRB 001018 at Keck
- IPN triangulation of GRB001219
- GRB 001109: deep JHK upper limits
- IPN TRIANGULATION OF GRB001105
- IPN TRIANGULATION OF GRB001020
- GRB 000926 Chandra Observation
- GRB000926 K'-band Observation
- HST/STIS observations of the host galaxy of GRB 980329
- SGR 1806-20 burst activity
- IPN localization of GRB000730B
- IPN localization of GRB000730B
- GRB 990510: Possible detection of a host galaxy
- GRB 990510 Host Galaxy Discovery
- GRB 990712: Late time HST/STIS Observations
- GRB 000630: Detection of the Optical Afterglow
- GRB000616 [IPN Position]
- GRB 000418: Detection of the Host Galaxy
- GRB000529: BeppoSAX NFI follow-up preliminary analysis