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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"

4572 results found.

  1. GRB 240828B: Swift-XRT afterglow detection
  2. Swift GRB240829.16: Global MASTER-Net observations report
  3. GRB 240825A: Upper limits from a neutrino search with IceCube
  4. Fermi trigger No 746438824: Global MASTER-Net observations report
  5. GRB 240824A: GIT optical upper limit
  6. GRB 240825A: Swift-XRT refined Analysis
  7. GRB 240824B: Fermi GBM Observation
  8. GRB 240824A: SVOM/C-GFT optical upper limit
  9. Fermi GRB 240824C: Global MASTER-Net observations report
  10. GRB 240824C: Fermi GBM Final Localization
  11. GRB 240824B: MAXI/GSC detection
  12. GRB 240824B: Fermi GBM Final Real-time Localization
  13. GRB 240824A: Retraction of GCN 37255
  14. GRB 240824A: Skynet Optical Afterglow Discovery
  15. Swift GRB240824.04: Global MASTER-Net observations report
  16. Fermi GRB 240821A: Global MASTER-Net observations report
  17. GRB240821A: EIRSAT-1 GMOD Detection
  18. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  19. Fermi GRB 240821B: Global MASTER-Net observations report
  20. GRB 240821B: Fermi GBM Final Localization
  21. Trigger 1249878: Swift detection of another burst from SGR 1E 1841-045 / Kes 73
  22. Fermi trigger No 745873283: Global MASTER-Net observations report
  23. Fermi trigger No 745871958: Global MASTER-Net observations report
  24. IceCube-240721A: AT2023qqp and AT2024pge likely unrelated
  25. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  26. Fermi trigger No 745501396: Global MASTER-Net observations report
  27. IceCube-240808A: Upper limits from a search for additional neutrino events in IceCube
  28. GRB 240811A: Swift-XRT refined Analysis
  29. Fermi trigger No 745057312: Global MASTER-Net observations report
  30. GRB 240808A: AstroSat CZTI detection
  31. GRB 240809A: Swift-XRT refined Analysis
  32. GRB 240807B: AstroSat CZTI detection of a short burst
  33. EP EP240807a: Global MASTER-Net observations report
  34. EP EP240806a: Global MASTER-Net observations report
  35. Fermi trigger No 744761058: Global MASTER-Net observations report
  36. Fermi trigger No 744629911: Global MASTER-Net observations report
  37. GRB 240624B: VZLUSAT-2 detection
  38. GRB 240619C: VZLUSAT-2 detection
  39. GRB 240805B: Swift-XRT refined Analysis
  40. GRB 240805A: Swift-XRT refined Analysis
  41. GRB 240805B: Swift detection of a burst
  42. Fermi GRB 240804A: Global MASTER-Net observations report
  43. Fermi GRB 240801A: Global MASTER-Net observations report
  44. GRB 240730A: Swift-XRT refined Analysis
  45. Fermi trigger No 743953682: Global MASTER-Net observations report
  46. GRB 240727A: Swift-XRT refined Analysis
  47. GRB 240726B: AstroSat CZTI detection of a short burst
  48. IceCube-240725A: Upper limits from a search for additional neutrino events in IceCube
  49. Fermi trigger No 743219692: Global MASTER-Net observations report
  50. GRB 240720A: AstroSat CZTI detection
  51. GRB 240720A: Fermi GBM observation
  52. GRB 240720A: Swift detection of a burst
  53. Fermi GRB 240718A: Global MASTER-Net observations report
  54. LAT GRB240718.27: Global MASTER-Net observations report
  55. Konus-Wind detection of GRB 240715A
  56. GRB240715A: GRANDMA Optical Upper Limits
  57. JinShan confirmation of the EP-WXT source triggered on July 14th due to a flaring star
  58. EP240703b: GSP optical upper limit
  59. Fermi Gamma-ray Burst Monitor trigger 741911057/240705933 is not a GRB
  60. GRB 240705A: Fermi GBM Final Real-time Localization
  61. EP240703b: EP-WXT detection of a fast X-ray transient
  62. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  63. GRB 240624B: GRBAlpha detection
  64. GRB240624A: Fermi GBM Observation
  65. Swift GRB 240624A: Global MASTER-Net observations report
  66. Fermi GRB 240624A: Global MASTER-Net observations report
  67. GRB 240624B: Fermi GBM Final Real-time Localization
  68. Fermi trigger No 740949590: Global MASTER-Net observations report
  69. GRB 240624A: Fermi GBM Final Real-time Localization
  70. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  71. Fermi trigger No 740430582: Global MASTER-Net observations report
  72. GRB240615A: 1.3m DFOT optical upper limit
  73. Fermi trigger No 740221779: Global MASTER-Net observations report
  74. GRB 240612A: Fermi GBM Final Real-time Localization
  75. Konus-Wind detection of GRB 240607A
  76. Fermi GRB 240610A: Global MASTER-Net observations report
  77. IPN triangulation of GRB 240607A
  78. Fermi GRB 240607A: Global MASTER-Net observations report
  79. GRB 240606B: Swift-XRT afterglow detection
  80. Fermi GRB 240604A: Global MASTER-Net observations report
  81. GRB 240605C: Fermi GBM Final Real-time Localization
  82. Fermi GRB 240602A: Global MASTER-Net observations report
  83. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  84. GRB 240529A: AKO Optical Afterglow Detection
  85. LIGO/Virgo/KAGRA S240530a: Identification of a GW compact binary merger candidate
  86. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  87. LAT GRB240527.59: Global MASTER-Net observations report
  88. Fermi GRB 240527B: Global MASTER-Net observations report
  89. GRB 240527A: Fermi GBM Final Real-time Localization
  90. Fermi trigger No 738348224: Global MASTER-Net observations report
  91. Fermi trigger No 738330463: Global MASTER-Net observations report
  92. GRB 240523A: Swift-XRT refined Analysis
  93. GRB 240513A: Swift-XRT afterglow detection
  94. Fermi trigger No 737996942: Global MASTER-Net observations report
  95. GRB 240504A: VZLUSAT-2 detection
  96. Fermi trigger No 737788024: Global MASTER-Net observations report
  97. Fermi GRB 240517A: Global MASTER-Net observations report
  98. GRB 240516A ATCA radio observations
  99. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  100. Fermi trigger No 737523389: Global MASTER-Net observations report

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