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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"

54 results found.

  1. Fermi GRB 251002A: Global MASTER-Net observations report
  2. GRB 250725A: Swift/UVOT Upper Limits
  3. EP250511a: Global MASTER-Net observations report
  4. IceCube Alert 250309.32: Global MASTER-Net observations report
  5. Fermi trigger No 736197684: Global MASTER-Net observations report
  6. GRB 240403A: Fermi GBM Detection
  7. Swift GRB240305.18: Global MASTER-Net observations report
  8. Swift GRB240305.16: Global MASTER-Net observations report
  9. Swift GRB 240303A: Global MASTER-Net observations report
  10. GRB 240124B: AstroSat CZTI detection
  11. Swift GRB231230.06: Global MASTER-Net observations report
  12. Swift GRB231214.85: Global MASTER-Net observations report
  13. IPN triangulation of GRB 231129C
  14. GRB 231123C (short): Glowbug gamma-ray detection
  15. GRB 230304D: AstroSat CZTI detection
  16. Fermi trigger No 683537972: Global MASTER-Net observations report
  17. Fermi trigger No 676537486: Global MASTER-Net observations report
  18. GRB 220101A: Swift-XRT refined Analysis
  19. GRB 210424B: AstroSat CZTI detection
  20. Fermi GRB 201121A: Global MASTER-Net observations report
  21. Swift GRB 201029A: Global MASTER-Net observations report
  22. Fermi GRB 200629A: Global MASTER-Net observations report
  23. LIGO/Virgo S200224ca: Updated Sky Localization and EM Bright Classification
  24. LIGO/Virgo S200128d: Global MASTER-Net observations report
  25. Swift GRB200109.07: Global MASTER-Net observations report
  26. Fermi trigger No 598543714: Global MASTER-Net observations report
  27. Konus-Wind observation of GRB 191218A
  28. GRB 190823A: MAXI/GSC detection
  29. LIGO/Virgo S190512at: Updated sky localization
  30. GRB 180510A: Swift/UVOT followup observations
  31. GRB 180404B: Swift/UVOT Detection
  32. BAT trigger 778435 is not a GRB.
  33. LIGO/Virgo G297595: Las Cumbres Observatory Optical Follow-Up
  34. GRB 170803A: Swift/UVOT Detection
  35. GRB 160821B: Swift/UVOT Upper Limits
  36. Konus-Wind observation of GRB 150902A
  37. GRB 150821A: Fermi GBM detection
  38. Trigger 643078: Swift detection of H1743-322
  39. GRB 140129B: Swift-XRT refined Analysis
  40. GRB 140102A: Swift/UVOT Detection
  41. GRB 120215A: Swift/UVOT Upper Limits
  42. GRB 111222A: Swift-XRT observations
  43. GRB 100621A: Swift XRT refined analysis
  44. GRB 090807: Swift/UVOT Upper Limits
  45. Konus-Wind observation of GRB 071020
  46. GRB 070419A: Early Super-LOTIS Observations
  47. GRB061222A Swift/UVOT: Upper Limits
  48. GRB050712: Swift UVOT Observation of Afterglow Emission
  49. 030331 NOT A GRB
  50. GRB 030329: visual observations
  51. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  52. GRB 020322 optical observations
  53. GRB000201 Optical Observations
  54. VLT spectrum of GRB990510

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