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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"

5401 results found.

  1. GRB 240801A: Fermi GBM Final Real-time Localization
  2. Fermi trigger No 744128417: Global MASTER-Net observations report
  3. Fermi GRB 240730B: Global MASTER-Net observations report
  4. Fermi trigger No 743953682: Global MASTER-Net observations report
  5. Fermi GRB 240727A: Global MASTER-Net observations report
  6. Fermi trigger No 743868421: Global MASTER-Net observations report
  7. GRB 240627A: GRBAlpha detection
  8. Fermi GRB 240726A: Global MASTER-Net observations report
  9. GRB240727A: Skynet Optical Afterglow Observations
  10. GRB 240727A: Swift detection of a burst
  11. IceCube-240725A: Upper limits from a search for additional neutrino events in IceCube
  12. IceCube Alert 240725.22: Global MASTER-Net observations report
  13. Fermi trigger No 743219692: Global MASTER-Net observations report
  14. Fermi GRB 240718A: Global MASTER-Net observations report
  15. LIGO/Virgo/KAGRA S240716b: Identification of a GW compact binary merger candidate
  16. GRB 240715A: Fermi GBM Final Real-time Localization
  17. EP240708a: GSP optical upper limit
  18. GRB 240712A: Swift detection of a burst
  19. Fermi trigger No 742405878: Global MASTER-Net observations report
  20. EP240708a: NOT optical observations
  21. EP240702a: TRT optical upper limits
  22. EP240703a: BTA observations
  23. LIGO/Virgo/KAGRA S240703ad: Identification of a GW compact binary merger candidate
  24. EP240702a: Swift/XRT upper limit
  25. Fermi trigger No 741448122: Global MASTER-Net observations report
  26. Fermi trigger No 741356809: Global MASTER-Net observations report
  27. IPN triangulation of GRB 240619C
  28. Konus-Wind detection of GRB 240619A
  29. Fermi GRB 240625B: Global MASTER-Net observations report
  30. Fermi trigger No 740744838: Global MASTER-Net observations report
  31. GRB 240619A: GRBAlpha detection
  32. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  33. GRB 240619A: Fermi GBM Observation
  34. Fermi trigger No 740430582: Global MASTER-Net observations report
  35. GRB 240619A: BALROG localization (Fermi Trigger 740461416 / GRB 240619155)
  36. GRB 240619A: Fermi GBM Final Real-time Localization
  37. Fermi GRB 240616A: Global MASTER-Net observations report
  38. GRB 240615A: GOTO optical upper limits
  39. Fermi trigger No 740166710: Global MASTER-Net observations report
  40. GRB 240603A: VZLUSAT-2 detection
  41. GRB 240610A: Fermi GBM Final Real-time Localization
  42. IPN triangulation of GRB 240607A
  43. Fermi trigger No 739506569: Global MASTER-Net observations report
  44. GRB 240608A: Fermi GBM Final Real-time Localization
  45. Fermi GRB 240607A: Global MASTER-Net observations report
  46. Swift GRB240606.15: Global MASTER-Net observations report
  47. Swift Trigger 1235109: a possible GRB 240606A
  48. Fermi GRB 240604A: Global MASTER-Net observations report
  49. Fermi GRB 240603C: Global MASTER-Net observations report
  50. GRB 240603A: Fermi GBM Final Localization
  51. GRB 240603C: BALROG localization (Fermi Trigger 739102156 / GRB 240603423)
  52. GRB 240529A: MASTER prompt OT detection
  53. Fermi GRB 240602A: Global MASTER-Net observations report
  54. GRB 240602A: Fermi GBM Final Real-time Localization
  55. GRB 240529A: Skynet Optical Observations
  56. GRB240529A: BOOTES-6/DPRT optical detection
  57. GRB 240529A: Swift detection of a burst with an optical counterpart
  58. Swift GRB240529.12: Global MASTER-Net observations report
  59. GRB 240527B: Fermi GBM Observation
  60. GRB 240527B: Fermi-LAT detection
  61. LAT GRB240527.59: Global MASTER-Net observations report
  62. Fermi GRB 240527B: Global MASTER-Net observations report
  63. GRB 240527B: Fermi GBM Final Localization
  64. GRB 240527B: BALROG localization (Fermi Trigger 738511436 / GRB 240527586)
  65. GRB 240523A: Swift-BAT refined analysis
  66. Fermi trigger No 738348224: Global MASTER-Net observations report
  67. Fermi trigger No 738330463: Global MASTER-Net observations report
  68. LIGO/Virgo/KAGRA S240525p: Identification of a GW compact binary merger candidate
  69. Fermi GBM Sub-Threshold Detection of GRB 240516B
  70. Fermi trigger No 737996942: Global MASTER-Net observations report
  71. GRB 240516B: AstroSat CZTI detection
  72. GRB 240514B: VZLUSAT-2 detection
  73. GRB 240504A: VZLUSAT-2 detection
  74. Fermi trigger No 737788024: Global MASTER-Net observations report
  75. Fermi GRB 240517A: Global MASTER-Net observations report
  76. IPN triangulation of GRB 240514B (short)
  77. GRB 240516A: AstroSat CZTI detection
  78. GRB 240516A: Fermi GBM Observation
  79. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  80. Fermi trigger No 737523389: Global MASTER-Net observations report
  81. GRB 240516A: Swift detection of a burst
  82. Swift GRB240516.15: Global MASTER-Net observations report
  83. MAXI GRB240514.78: Global MASTER-Net observations report
  84. GRB 240514B: GRBAlpha detection
  85. GRB 240514B: Fermi GBM Detection
  86. LIGO/Virgo/KAGRA S240514c: Identification of a GW compact binary merger candidate
  87. GRB 240514B: Fermi GBM Final Real-time Localization
  88. LAT GRB240513.31: Global MASTER-Net observations report
  89. Fermi trigger No 737277727: Global MASTER-Net observations report
  90. Fermi trigger No 737247400: Global MASTER-Net observations report
  91. GRB 240511A : MITSuME Akeno optical upper limits
  92. LIGO/Virgo/KAGRA S240511i: Identification of a GW compact binary merger candidate
  93. LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
  94. Fermi trigger No 736564880: Global MASTER-Net observations report
  95. GRB 240502C: Zeiss-1000 at Koshka observatory observations of GOTO optical counterpart candidates
  96. GRB 240503A: AstroSat CZTI detection
  97. Fermi trigger No 736387941: Global MASTER-Net observations report
  98. LXT 240402A / GRB 240402B: VLT X-shooter redshift of host
  99. Fermi trigger No 736379109: Global MASTER-Net observations report
  100. GRB 240502C: GOTO possible optical counterpart candidates

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