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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"

3040 results found.

  1. Fermi-GBM Sub-Threshold Detection of GRB 241112B
  2. GRB 241112B: SVOM/GRM observation
  3. GRB 241112B : detection of a long GRB by SVOM/ECLAIRs
  4. Fermi trigger No 752990530: Global MASTER-Net observations report
  5. Fermi trigger No 752878030: Global MASTER-Net observations report
  6. EP241107a: AKO Optical Afterglow Follow-Up Observations
  7. GRB 240511A: LCO upper limits
  8. Fermi GRB 241105A: Global MASTER-Net observations report
  9. Fermi GRB 241104A: Global MASTER-Net observations report
  10. EP241101a: EP-FXT observations update
  11. Fermi trigger No 752365806: Global MASTER-Net observations report
  12. EP241103a: Swift XRT detection and improved X-ray position
  13. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  14. GRB 241101A: Swift detection of a burst
  15. Fermi trigger No 752083996: Global MASTER-Net observations report
  16. EP EP241030a: Global MASTER-Net observations report
  17. Fermi trigger No 752006065: Global MASTER-Net observations report
  18. GRB 241030B: Swift detection of a burst
  19. GRB 240912A: radio detection with the VLA
  20. Fermi GRB 241030A: Global MASTER-Net observations report
  21. GRB 241026A: SAO RAS observations of possible optical afterglow
  22. Fermi GRB 241026A: Global MASTER-Net observations report
  23. GRB 241026A: Prompt enhanced Swift-XRT position
  24. EP241021a: optical follow-up observations with Xinglong Observatory
  25. Fermi GRB 241025A: Global MASTER-Net observations report
  26. IPN triangulation of GRB 241021A (long)
  27. GRB241017A: 1.3m DFOT optical upper limit
  28. Fermi trigger No 750788395: Global MASTER-Net observations report
  29. GRB 241017A : Detection of a weak and soft long duration GRB by SVOM/ECLAIRs
  30. Fermi GRB 241016A: Global MASTER-Net observations report
  31. GRB 240916A: radio detection with the VLA
  32. GRB241013A: REM observations
  33. Fermi trigger No 750211959: Global MASTER-Net observations report
  34. IceCube Alert 241006.94: Global MASTER-Net observations report
  35. EP EP240930a: Global MASTER-Net observations report
  36. Fermi GRB 240929A: Global MASTER-Net observations report
  37. LIGO/Virgo S240919bn: GOTO optical upper limits
  38. GRB 240918B: AstroSat CZTI detection
  39. EP240919a: EP-FXT follow-up observation update
  40. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  41. GRB 240918B: Fermi GBM Detection
  42. GRB 240912A: Swift-BAT refined analysis
  43. Fermi GRB 240908A: Global MASTER-Net observations report
  44. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  45. GRB 240902B: AstroSat CZTI detection of a long burst
  46. GRB 240825A: Montarrenti Observatory optical follow-up observations
  47. Fermi trigger No 746923430: Global MASTER-Net observations report
  48. Fermi trigger No 746587425: Global MASTER-Net observations report
  49. Swift GRB240829.16: Global MASTER-Net observations report
  50. Fermi trigger No 746438824: Global MASTER-Net observations report
  51. GRB 240824A: GIT optical upper limit
  52. GRB 240825A: AKO Optical Follow-Up Observations
  53. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  54. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  55. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  56. Fermi GRB 240821B: Global MASTER-Net observations report
  57. Fermi trigger No 745866488: Global MASTER-Net observations report
  58. Trigger 1249878: Swift detection of another burst from SGR 1E 1841-045 / Kes 73
  59. EP240816a: EP detection of a fast X-ray transient and follow-up observation
  60. Fermi GRB 240814B: Global MASTER-Net observations report
  61. GRB 240808A: AstroSat CZTI detection
  62. GRB 240808A: SVOM/GRM observation
  63. EP EP240807a: Global MASTER-Net observations report
  64. EP EP240806a: Global MASTER-Net observations report
  65. GRB 240805B: Swift-BAT refined analysis
  66. Fermi trigger No 744629911: Global MASTER-Net observations report
  67. Fermi GRB 240805A: Global MASTER-Net observations report
  68. Fermi GRB 240804A: Global MASTER-Net observations report
  69. Fermi trigger No 744459130: Global MASTER-Net observations report
  70. Fermi trigger No 744128417: Global MASTER-Net observations report
  71. GRB240730A: BOOTES-5/JGT early optical upper limit
  72. GRB 240720A: Swift-BAT refined analysis
  73. Fermi trigger No 743219692: Global MASTER-Net observations report
  74. GRB 240721A: Fermi GBM Final Real-time Localization
  75. Fermi GRB 240720A: Global MASTER-Net observations report
  76. Fermi-LAT gamma-ray observations of IceCube-cascade-240714A
  77. Fermi trigger No 742405878: Global MASTER-Net observations report
  78. Fermi trigger No 742317942: Global MASTER-Net observations report
  79. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  80. Fermi trigger No 741448122: Global MASTER-Net observations report
  81. Fermi trigger No 741356809: Global MASTER-Net observations report
  82. GRB 240624A: Swift-BAT refined analysis
  83. Fermi trigger No 740949590: Global MASTER-Net observations report
  84. EP240617a: tentative Swift/XRT detection of the afterglow
  85. EP240618a: GRANDMA Optical Upper Limits
  86. LIGO/Virgo S240615dg: GRANDMA/FRAM-CTA-N Observations
  87. Fermi trigger No 740430582: Global MASTER-Net observations report
  88. Fermi trigger No 740221779: Global MASTER-Net observations report
  89. Fermi GRB 240616A: Global MASTER-Net observations report
  90. Fermi trigger No 740166710: Global MASTER-Net observations report
  91. Fermi trigger No 739506569: Global MASTER-Net observations report
  92. Fermi GRB 240607A: Global MASTER-Net observations report
  93. GRB 240607A: AstroSat CZTI detection of bright long burst
  94. Fermi GRB 240604A: Global MASTER-Net observations report
  95. GRB 240603B: Swift detection of a possible burst
  96. Fermi GRB 240602A: Global MASTER-Net observations report
  97. GRB 240529A: AKO Optical Afterglow Detection
  98. Fermi trigger No 738348224: Global MASTER-Net observations report
  99. Fermi trigger No 738330463: Global MASTER-Net observations report
  100. Fermi trigger No 737996942: Global MASTER-Net observations report

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