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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"

4715 results found.

  1. Fermi trigger No 744544656: Global MASTER-Net observations report
  2. EP240801a: BTA BVRI photometry
  3. Fermi GRB 240805A: Global MASTER-Net observations report
  4. EP240801a: Continued optical observations at ZTSh (CraO)
  5. EP240804a: LCOGT optical counterpart detection
  6. Fermi GRB 240804A: Global MASTER-Net observations report
  7. EP240802a: Montarrenti Observatory optical upper limit
  8. EP240801a: Osservatorio Astronomico Nastro Verde upper limit
  9. Fermi trigger No 744278264: Global MASTER-Net observations report
  10. EP240801a: GRANDMA and Kilonova-Catcher optical observations
  11. EP240801a: Leavitt Observatory optical observations
  12. EP240801a: GMG observation
  13. EP240801a: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  14. Fermi GRB 240801A: Global MASTER-Net observations report
  15. GRB 240801A: Fermi GBM Final Real-time Localization
  16. Fermi trigger No 744128417: Global MASTER-Net observations report
  17. Fermi GRB 240730B: Global MASTER-Net observations report
  18. Fermi trigger No 743953682: Global MASTER-Net observations report
  19. Fermi GRB 240727A: Global MASTER-Net observations report
  20. Fermi trigger No 743868421: Global MASTER-Net observations report
  21. GRB 240627A: GRBAlpha detection
  22. Fermi GRB 240726A: Global MASTER-Net observations report
  23. GRB240727A: Skynet Optical Afterglow Observations
  24. GRB 240727A: Swift detection of a burst
  25. IceCube-240725A: Upper limits from a search for additional neutrino events in IceCube
  26. IceCube Alert 240725.22: Global MASTER-Net observations report
  27. Fermi trigger No 743219692: Global MASTER-Net observations report
  28. Fermi GRB 240718A: Global MASTER-Net observations report
  29. LIGO/Virgo/KAGRA S240716b: Identification of a GW compact binary merger candidate
  30. GRB 240715A: Fermi GBM Final Real-time Localization
  31. EP240708a: GSP optical upper limit
  32. GRB 240712A: Swift detection of a burst
  33. Fermi trigger No 742405878: Global MASTER-Net observations report
  34. EP240708a: NOT optical observations
  35. EP240702a: TRT optical upper limits
  36. EP240703a: BTA observations
  37. LIGO/Virgo/KAGRA S240703ad: Identification of a GW compact binary merger candidate
  38. EP240702a: Swift/XRT upper limit
  39. Fermi trigger No 741448122: Global MASTER-Net observations report
  40. Fermi trigger No 741356809: Global MASTER-Net observations report
  41. IPN triangulation of GRB 240619C
  42. Konus-Wind detection of GRB 240619A
  43. Fermi GRB 240625B: Global MASTER-Net observations report
  44. Fermi trigger No 740744838: Global MASTER-Net observations report
  45. GRB 240619A: GRBAlpha detection
  46. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  47. GRB 240619A: Fermi GBM Observation
  48. Fermi trigger No 740430582: Global MASTER-Net observations report
  49. GRB 240619A: BALROG localization (Fermi Trigger 740461416 / GRB 240619155)
  50. GRB 240619A: Fermi GBM Final Real-time Localization
  51. Fermi GRB 240616A: Global MASTER-Net observations report
  52. GRB 240615A: GOTO optical upper limits
  53. Fermi trigger No 740166710: Global MASTER-Net observations report
  54. GRB 240603A: VZLUSAT-2 detection
  55. GRB 240610A: Fermi GBM Final Real-time Localization
  56. IPN triangulation of GRB 240607A
  57. Fermi trigger No 739506569: Global MASTER-Net observations report
  58. GRB 240608A: Fermi GBM Final Real-time Localization
  59. Fermi GRB 240607A: Global MASTER-Net observations report
  60. Swift GRB240606.15: Global MASTER-Net observations report
  61. Swift Trigger 1235109: a possible GRB 240606A
  62. Fermi GRB 240604A: Global MASTER-Net observations report
  63. Fermi GRB 240603C: Global MASTER-Net observations report
  64. GRB 240603A: Fermi GBM Final Localization
  65. GRB 240603C: BALROG localization (Fermi Trigger 739102156 / GRB 240603423)
  66. GRB 240529A: MASTER prompt OT detection
  67. Fermi GRB 240602A: Global MASTER-Net observations report
  68. GRB 240602A: Fermi GBM Final Real-time Localization
  69. GRB 240529A: Skynet Optical Observations
  70. GRB240529A: BOOTES-6/DPRT optical detection
  71. GRB 240529A: Swift detection of a burst with an optical counterpart
  72. Swift GRB240529.12: Global MASTER-Net observations report
  73. GRB 240527B: Fermi GBM Observation
  74. GRB 240527B: Fermi-LAT detection
  75. LAT GRB240527.59: Global MASTER-Net observations report
  76. Fermi GRB 240527B: Global MASTER-Net observations report
  77. GRB 240527B: Fermi GBM Final Localization
  78. GRB 240527B: BALROG localization (Fermi Trigger 738511436 / GRB 240527586)
  79. GRB 240523A: Swift-BAT refined analysis
  80. Fermi trigger No 738348224: Global MASTER-Net observations report
  81. Fermi trigger No 738330463: Global MASTER-Net observations report
  82. LIGO/Virgo/KAGRA S240525p: Identification of a GW compact binary merger candidate
  83. Fermi GBM Sub-Threshold Detection of GRB 240516B
  84. Fermi trigger No 737996942: Global MASTER-Net observations report
  85. GRB 240516B: AstroSat CZTI detection
  86. GRB 240514B: VZLUSAT-2 detection
  87. GRB 240504A: VZLUSAT-2 detection
  88. Fermi trigger No 737788024: Global MASTER-Net observations report
  89. Fermi GRB 240517A: Global MASTER-Net observations report
  90. IPN triangulation of GRB 240514B (short)
  91. GRB 240516A: AstroSat CZTI detection
  92. GRB 240516A: Fermi GBM Observation
  93. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  94. Fermi trigger No 737523389: Global MASTER-Net observations report
  95. GRB 240516A: Swift detection of a burst
  96. Swift GRB240516.15: Global MASTER-Net observations report
  97. MAXI GRB240514.78: Global MASTER-Net observations report
  98. GRB 240514B: GRBAlpha detection
  99. GRB 240514B: Fermi GBM Detection
  100. LIGO/Virgo/KAGRA S240514c: Identification of a GW compact binary merger candidate

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