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"360 results found.
- XRF 090702: Swift-XRT refined analysis
- A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
- SGR J1550-5418
- IBAS Alert N. 5442 is not a GRB
- Suzaku ToO Observation of AXP 1E 1547.0-5408
- Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
- GRB 090111: Swift UVOT Upper Limits
- GRB 081222: Swift XRT refined analysis
- INTEGRAL ToO observation of the AXP 1E 1547.0-5408
- AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
- GRB080818B: GLAST Burst Monitor detection
- GRB 080520: Swift XRT Refined Analysis
- GRB 080330A: ROTSE-III Detection of Optical Counterpart
- GRB 080205: Swift XRT refined analysis
- GRB 080121: Upper limit on X-ray afterglow
- GRB080120: Swift XRT position
- Swift XRT follow-up observations of GRB071008
- GRB 071003: XRT refined analysis
- GRB 070729: Swift-XRT refined analysis
- GRB 070520B: Swift-XRT refined analysis
- GRB 070520A: Swift-XRT refined analysis
- GRB070107: Swift/XRT refined analysis
- GRB061222B: Swift-XRT Refined Analysis
- GRB061025: Swift XRT refined analysis
- IGR J08408-4503 (= V* LM Vel): Swift detection of a transient
- GRB 060729: An update on the late-time Swift observations
- GRB 060926: Swift XRT refined analysis
- Two bright bursts from SGR 1806-20 detected with IBAS
- GRB060213: Swift XRT observations and possible afterglow candidate
- GRB060204a: Swift XRT Detection of an Afterglow Candidate
- Swift XRT Observation of GRB 060204C
- GRB060203: Swift XRT Team Refined Analysis
- Possible GRB 050922 detected by INTEGRAL
- GRB 050904: early Swift XRT analysis results
- GRB 050716: Refined XRT analysis.
- GRB 050509B: Swift/XRT refined analysis
- GRB 050502 - A long GRB detected with INTEGRAL
- SGR 1806-20, RHESSI observations of the 041227 giant flare
- GRB041220: Swift-BAT burst
- Swift-BAT detection of the bright long burst GRB041219
- GRB 041219 - A long GRB detected by INTEGRAL
- XMM-Newton Images of GRB 040827
- XRF040701: Second-Epoch Chandra Observations
- XRF040701: First-Epoch Chandra Observations
- GRB040511 (=H3218): A Long GRB Localized by HETE WXM and SXC
- GRBlog: Compilation of all GCN Circ. data
- IPN detection of renewed activity from SGR1806-20
- IPN triangulation of GRB030131 - CORRECTION
- IPN triangulation of GRB021119 (annulus)
- IPN triangulation of GRB021025 (annulus)
- GRB020813: optical afterglow
- 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
- IPN triangulation of GRB020525
- SGR 1900+14, Chandra observations
- IPN triangulation of GRB 001004
- GRB 991216--Summary of RXTE Observations