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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"

5051 results found.

  1. Fermi trigger No 745873283: Global MASTER-Net observations report
  2. Fermi trigger No 745871958: Global MASTER-Net observations report
  3. IceCube-240721A: AT2023qqp and AT2024pge likely unrelated
  4. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  5. Fermi trigger No 745501396: Global MASTER-Net observations report
  6. IceCube-240808A: Upper limits from a search for additional neutrino events in IceCube
  7. GRB 240811A: Swift-XRT refined Analysis
  8. Fermi trigger No 745057312: Global MASTER-Net observations report
  9. GRB 240808A: AstroSat CZTI detection
  10. GRB 240809A: Swift-XRT refined Analysis
  11. GRB 240807B: AstroSat CZTI detection of a short burst
  12. EP EP240807a: Global MASTER-Net observations report
  13. EP EP240806a: Global MASTER-Net observations report
  14. Fermi trigger No 744761058: Global MASTER-Net observations report
  15. Fermi trigger No 744629911: Global MASTER-Net observations report
  16. GRB 240624B: VZLUSAT-2 detection
  17. GRB 240619C: VZLUSAT-2 detection
  18. GRB 240805B: Swift-XRT refined Analysis
  19. GRB 240805A: Swift-XRT refined Analysis
  20. GRB 240805B: Swift detection of a burst
  21. Fermi GRB 240804A: Global MASTER-Net observations report
  22. Fermi GRB 240801A: Global MASTER-Net observations report
  23. GRB 240730A: Swift-XRT refined Analysis
  24. Fermi trigger No 743953682: Global MASTER-Net observations report
  25. GRB 240727A: Swift-XRT refined Analysis
  26. GRB 240726B: AstroSat CZTI detection of a short burst
  27. IceCube-240725A: Upper limits from a search for additional neutrino events in IceCube
  28. Fermi trigger No 743219692: Global MASTER-Net observations report
  29. GRB 240720A: AstroSat CZTI detection
  30. GRB 240720A: Fermi GBM observation
  31. GRB 240720A: Swift detection of a burst
  32. Fermi GRB 240718A: Global MASTER-Net observations report
  33. LAT GRB240718.27: Global MASTER-Net observations report
  34. Konus-Wind detection of GRB 240715A
  35. GRB240715A: GRANDMA Optical Upper Limits
  36. JinShan confirmation of the EP-WXT source triggered on July 14th due to a flaring star
  37. EP240703b: GSP optical upper limit
  38. Fermi Gamma-ray Burst Monitor trigger 741911057/240705933 is not a GRB
  39. GRB 240705A: Fermi GBM Final Real-time Localization
  40. EP240703b: EP-WXT detection of a fast X-ray transient
  41. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  42. GRB 240624B: GRBAlpha detection
  43. GRB240624A: Fermi GBM Observation
  44. Swift GRB 240624A: Global MASTER-Net observations report
  45. Fermi GRB 240624A: Global MASTER-Net observations report
  46. GRB 240624B: Fermi GBM Final Real-time Localization
  47. Fermi trigger No 740949590: Global MASTER-Net observations report
  48. GRB 240624A: Fermi GBM Final Real-time Localization
  49. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  50. Fermi trigger No 740430582: Global MASTER-Net observations report
  51. GRB240615A: 1.3m DFOT optical upper limit
  52. Fermi trigger No 740221779: Global MASTER-Net observations report
  53. GRB 240612A: Fermi GBM Final Real-time Localization
  54. Konus-Wind detection of GRB 240607A
  55. Fermi GRB 240610A: Global MASTER-Net observations report
  56. IPN triangulation of GRB 240607A
  57. Fermi GRB 240607A: Global MASTER-Net observations report
  58. GRB 240606B: Swift-XRT afterglow detection
  59. Fermi GRB 240604A: Global MASTER-Net observations report
  60. GRB 240605C: Fermi GBM Final Real-time Localization
  61. Fermi GRB 240602A: Global MASTER-Net observations report
  62. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  63. GRB 240529A: AKO Optical Afterglow Detection
  64. LIGO/Virgo/KAGRA S240530a: Identification of a GW compact binary merger candidate
  65. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  66. LAT GRB240527.59: Global MASTER-Net observations report
  67. Fermi GRB 240527B: Global MASTER-Net observations report
  68. GRB 240527A: Fermi GBM Final Real-time Localization
  69. Fermi trigger No 738348224: Global MASTER-Net observations report
  70. Fermi trigger No 738330463: Global MASTER-Net observations report
  71. GRB 240523A: Swift-XRT refined Analysis
  72. GRB 240513A: Swift-XRT afterglow detection
  73. Fermi trigger No 737996942: Global MASTER-Net observations report
  74. GRB 240504A: VZLUSAT-2 detection
  75. Fermi trigger No 737788024: Global MASTER-Net observations report
  76. Fermi GRB 240517A: Global MASTER-Net observations report
  77. GRB 240516A ATCA radio observations
  78. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  79. Fermi trigger No 737523389: Global MASTER-Net observations report
  80. GRB 240514B: GOTO candidate optical counterpart
  81. GRB 240513A: Fermi GBM observation
  82. GRB 240513A: Swift-XRT observations
  83. LAT GRB240513.31: Global MASTER-Net observations report
  84. Fermi trigger No 737277727: Global MASTER-Net observations report
  85. Fermi trigger No 737247400: Global MASTER-Net observations report
  86. Fermi trigger No 737196587: Global MASTER-Net observations report
  87. Fermi trigger No 737168073: Global MASTER-Net observations report
  88. GRB 240511A: Swift-XRT refined Analysis
  89. Fermi trigger No 737173236: Global MASTER-Net observations report
  90. Fermi trigger No 737152719: Global MASTER-Net observations report
  91. LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
  92. Fermi trigger No 736967879: Global MASTER-Net observations report
  93. Fermi trigger No 736564880: Global MASTER-Net observations report
  94. IceCube-240424A: GRANDMA Optical Upper Limit of Fermi J2151.3+0220
  95. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  96. IPN triangulation of GRB 240501B and GRB 240501A - possible episodes of ultra long GRB
  97. GRB 240503A: AstroSat CZTI detection
  98. Fermi GRB 240501A: Global MASTER-Net observations report
  99. Fermi trigger No 736197684: Global MASTER-Net observations report
  100. GRB 240426A: VZLUSAT-2 detection

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