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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"

66 results found.

  1. The EP-WXT trigger 01709291839 is likely the known LMXB 4U 1745-203
  2. Konus-Wind detection of GRB 260411B
  3. IceCube Alert 251008A: Global MASTER-Net observations report
  4. GRB 251007B: SVOM/C-GFT upper limit
  5. EP250910a: Global MASTER-Net observations report
  6. GRB 250830C: AstroSat CZTI detection of a long burst
  7. Fermi GRB 250621A: Global MASTER-Net observations report
  8. GRB 250421B: AstroSat CZTI detection of a bright long burst
  9. LIGO/Virgo/KAGRA S250211aa: Updated Sky localization and EM Bright Classification
  10. Fermi trigger No 758442826: Global MASTER-Net observations report
  11. GRB 250101A: BOOTES-4/MET optical afterglow detection
  12. GRB 240809A: Swift/UVOT Detection
  13. Fermi GRB 240727A: Global MASTER-Net observations report
  14. GRB 240627A: AstroSat CZTI detection
  15. Konus-Wind detection of GRB 240607A
  16. EXO 0748-676: Swift-BAT refined analysis
  17. Trigger 1236151: Swift detection of EXO 0748-676
  18. Fermi GRB 240605A: Global MASTER-Net observations report
  19. GRB 240531A: AstroSat CZTI detection of a short burst
  20. GRB 240426A: AstroSat CZTI detection
  21. Fermi trigger No 709083929: Global MASTER-Net observations report
  22. GRB 230524B: AstroSat CZTI detection
  23. GRB 230427A: Swift/UVOT Detection
  24. GRB 221024A: Swift-XRT refined Analysis
  25. GRB 220702B: AstroSat CZTI detection
  26. GRB 220317A: Fermi GBM detection
  27. GRB 210330A: AstroSat CZTI detection
  28. Swift GRB 210318A: Global MASTER-Net observations report
  29. Fermi trigger No 636187116: Global MASTER-Net observations report
  30. GRB 210126A: AstroSat CZTI detection
  31. Fermi trigger No 630389391: Global MASTER-Net observations report
  32. Fermi trigger No 605756501: Global MASTER-Net observations report
  33. Fermi trigger No 600666048: Global MASTER-Net observations report
  34. Fermi trigger No 600448273: Global MASTER-Net observations report
  35. IceCube Alert 191215.47: Global MASTER-Net observations report
  36. LIGO/Virgo S190910d Global MASTER-Net observations report
  37. Konus-Wind observation of GRB 190206A
  38. GRB 161219B: POLAR Observation
  39. GRB 161108A: Swift/UVOT Upper Limits
  40. GRB 160408A: Swift/UVOT Upper Limits
  41. GRB 150627A: Swift/UVOT Detection
  42. GRB 150626A: Swift/UVOT Upper Limits
  43. Swift triggered on a source in Terzan 5 (trigger=637212)
  44. GRB 141130A: Mondy optical observations
  45. Konus-Wind observation of GRB 140906C
  46. SGR 1745-29 (Swift trigger 565443), Swift-BAT refined analysis
  47. GRB 110825A: Suzaku WAM observation of the prompt emission
  48. GRB 110205A: Suzaku WAM observation of the prompt emission
  49. GRB 101008A: Swift-BAT refined analysis
  50. GRB 101008A: Enhanced Swift-XRT position
  51. Konus-Wind observations of GRB 091010
  52. GRB090926B: Swift/UVOT Upper Limits
  53. GRB 090407: Swift UVOT Upper Limits
  54. Konus-Wind observation of GRB 081121
  55. Swift detection of AX J1749.1-2639
  56. Swift/UVOT observations of GRB080130
  57. Further Retractions of previous Swift-BAT triggers
  58. Retractions of previous Swift-BAT triggers
  59. GRB 060813: A long, bright GRB detected with Suzaku WAM
  60. GRB 060515: Super-LOTIS Observations
  61. GRB 050525, spectral lag pseudo-redshift
  62. GRB 050128: Swift XRT prompt afterglow position
  63. IPN confirmation of the reactivation of SGR1900+14
  64. GRB 990123: Reduced HST Images
  65. GRB 990123: Updated Keck Spectroscopy Results
  66. GRB980329 VLA observations

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