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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').
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"

53 results found.

  1. GRB 250725A: Swift/UVOT Upper Limits
  2. EP250511a: Global MASTER-Net observations report
  3. IceCube Alert 250309.32: Global MASTER-Net observations report
  4. Fermi trigger No 736197684: Global MASTER-Net observations report
  5. GRB 240403A: Fermi GBM Detection
  6. Swift GRB240305.18: Global MASTER-Net observations report
  7. Swift GRB240305.16: Global MASTER-Net observations report
  8. Swift GRB 240303A: Global MASTER-Net observations report
  9. GRB 240124B: AstroSat CZTI detection
  10. Swift GRB231230.06: Global MASTER-Net observations report
  11. Swift GRB231214.85: Global MASTER-Net observations report
  12. IPN triangulation of GRB 231129C
  13. GRB 231123C (short): Glowbug gamma-ray detection
  14. GRB 230304D: AstroSat CZTI detection
  15. Fermi trigger No 683537972: Global MASTER-Net observations report
  16. Fermi trigger No 676537486: Global MASTER-Net observations report
  17. GRB 220101A: Swift-XRT refined Analysis
  18. GRB 210424B: AstroSat CZTI detection
  19. Fermi GRB 201121A: Global MASTER-Net observations report
  20. Swift GRB 201029A: Global MASTER-Net observations report
  21. Fermi GRB 200629A: Global MASTER-Net observations report
  22. LIGO/Virgo S200224ca: Updated Sky Localization and EM Bright Classification
  23. LIGO/Virgo S200128d: Global MASTER-Net observations report
  24. Swift GRB200109.07: Global MASTER-Net observations report
  25. Fermi trigger No 598543714: Global MASTER-Net observations report
  26. Konus-Wind observation of GRB 191218A
  27. GRB 190823A: MAXI/GSC detection
  28. LIGO/Virgo S190512at: Updated sky localization
  29. GRB 180510A: Swift/UVOT followup observations
  30. GRB 180404B: Swift/UVOT Detection
  31. BAT trigger 778435 is not a GRB.
  32. LIGO/Virgo G297595: Las Cumbres Observatory Optical Follow-Up
  33. GRB 170803A: Swift/UVOT Detection
  34. GRB 160821B: Swift/UVOT Upper Limits
  35. Konus-Wind observation of GRB 150902A
  36. GRB 150821A: Fermi GBM detection
  37. Trigger 643078: Swift detection of H1743-322
  38. GRB 140129B: Swift-XRT refined Analysis
  39. GRB 140102A: Swift/UVOT Detection
  40. GRB 120215A: Swift/UVOT Upper Limits
  41. GRB 111222A: Swift-XRT observations
  42. GRB 100621A: Swift XRT refined analysis
  43. GRB 090807: Swift/UVOT Upper Limits
  44. Konus-Wind observation of GRB 071020
  45. GRB 070419A: Early Super-LOTIS Observations
  46. GRB061222A Swift/UVOT: Upper Limits
  47. GRB050712: Swift UVOT Observation of Afterglow Emission
  48. 030331 NOT A GRB
  49. GRB 030329: visual observations
  50. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  51. GRB 020322 optical observations
  52. GRB000201 Optical Observations
  53. VLT spectrum of GRB990510

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