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"
752 results found.
- GRB 240415A: Prompt Swift-XRT observations
- IPN triangulation of GRB 240410A
- X-ray transient EP240315a: second epoch e-MERLIN radio observations
- Fermi trigger No 731303574: Global MASTER-Net observations report
- IPN triangulation of GRB 240303B
- IPN triangulation of GRB 240125A (short)
- IPN triangulation of GRB 240123C (short)
- IPN triangulation of GRB 240112A (long)
- LIGO/Virgo/KAGRA S240107b: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231213ap: Identification of a GW compact binary merger candidate
- IPN triangulation of GRB 231129C
- IPN triangulation of GRB 231205A
- LIGO/Virgo/KAGRA S231206cc: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231206ca: Identification of a GW compact binary merger candidate
- GRB 231205B: Ondrejov D50 optical upper limit
- LIGO/Virgo/KAGRA S231129ac: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231127cg: Identification of a GW compact binary merger candidate
- Konus-Wind detection of GRB 231020A
- 231118A: Swift-UVOT Detection
- LIGO/Virgo/KAGRA S231119u: Identification of a GW compact binary merger candidate
- GRB 231118A: Las Cumbres optical detection
- LIGO/Virgo/KAGRA S231118an: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231118ab: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231118d: Identification of a GW compact binary merger candidate
- GRB 231117A: Swift detection of a bright short burst
- GRB 231115A: Non-detection in low-latency of gravitational waves with LIGO/Virgo/KAGRA
- LIGO/Virgo/KAGRA S231114n: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
- LIGO/Virgo/KAGRA S231113bw: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231110g: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231108u: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231104ac: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231102w: Identification of a GW compact binary merger candidate
- IPN triangulation of GRB 231020A
- LIGO/Virgo/KAGRA S231028bg: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231020ba: Identification of a GW compact binary merger candidate
- GRB 230911C: ATCA detection of possible radio counterpart
- GRB 231017A: Las Cumbres optical upper limit
- LIGO/Virgo/KAGRA S231008ap: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231005ah: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S231001aq: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230928cb: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230927be: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230927l: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230924an: Identification of a GW compact binary merger candidate
- IPN triangulation of GRB 230919A (short)
- LIGO/Virgo/KAGRA S230920al: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230919bj: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230914ak: Identification of a GW compact binary merger candidate
- IPN triangulation of GRB 230911D (long)
- IPN triangulation of GRB 230906A (short)
- LIGO/Virgo/KAGRA S230904n: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230831e: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230814ah: Updated Sky localization
- LIGO/Virgo/KAGRA S230824r: Identification of a GW compact binary merger candidate
- GRB 230812B: AstroSat LAXPC detection
- LIGO/Virgo/KAGRA S230820bq: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230819ax: Identification of a GW compact binary merger candidate
- Swift GRB230818.98: Global MASTER-Net observations report
- IPN triangulation of GRB 230815B
- LIGO/Virgo/KAGRA S230814r: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230811n: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230807f: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230806ak: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230805x: Identification of a GW compact binary merger candidate
- IPN triangulation of GRB 230803A
- LIGO/Virgo/KAGRA S230731an: Identification of a GW compact binary merger candidate
- GRB 230723B: MITSuME Ishigaki optical observation
- IPN triangulation of GRB 230723A (short)
- LIGO/Virgo/KAGRA S230723ac: Identification of a GW compact binary merger candidate
- IPN triangulation of GRB 230715D
- LIGO/Virgo/KAGRA S230709bi: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230708cf: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230707ai: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230706ah: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230702an: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230630bq: Identification of a GW compact binary merger candidate
- IPN triangulation of GRB 230625B (ultra-long)
- LIGO/Virgo/KAGRA S230628ax: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230627c: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230624av: Identification of a GW compact binary merger candidate
- GRB 230622A: Swift-XRT refined Analysis
- IPN triangulation of GRB 230616A (short)
- GRB 230614C: AstroSat CZTI detection
- LIGO/Virgo S230611l: Global MASTER-Net observations report
- LIGO/Virgo/KAGRA S230609u: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230608as: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230606d: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230605o: Identification of a GW compact binary merger candidate
- LIGO/Virgo/KAGRA S230601bf: Identification of a GW compact binary merger candidate
- IPN triangulation of GRB 230430A (short)
- IPN triangulation of GRB 230418A (short)
- GRB 230405B: Fermi GBM Observation
- IPN triangulation of GRB 230304B
- IPN triangulation of GRB 230308A (short/bright)
- Further improved IPN localization for GRB 230307A
- Swift GRB230311.84: Global MASTER-Net observations report
- Improved IPN localization for GRB 230307A
- IPN triangulation of GRB 230307A (long/very bright)
- Konus-Wind detection of GRB 230217A