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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

45522 results found.

  1. EP260214b: Einstein Probe detection of a fast X-ray transient
  2. EP260214a: Global MASTER-Net observations report
  3. EP260214a: Einstein Probe detection of an X-ray transient
  4. GRB 260212A: AstroSat CZTI detection
  5. GRB 260212A: Fermi GBM Observation
  6. EP260213a: Liverpool Telescope optical upper limits
  7. EP260213a: Global MASTER-Net observations report
  8. EP260213a: COLIBRÍ optical upper limits
  9. GRB 260212A: GECAM-B observation
  10. EP260213a: Optical upper limits with Kinder observations
  11. EP260213a: SVOM/VT optical upper limit
  12. EP260213a: Mondy R-band optical upper limit
  13. EP260213a: NUTTelA-TAO Early Optical Limits
  14. EP260213a: SVOM/C-GFT upper limit
  15. EP260213a: refined analysis of the EP-FXT observation
  16. EP260213a: Einstein Probe detection of a fast X-ray transient
  17. EP/WXT 01709258378: NOT optical upper limits
  18. GRB 260212A: SVOM/GRM observation of a long burst
  19. GRB 260213B: Fermi GBM Final Localization
  20. GRB 260213B: BALROG localization (Fermi Trigger 792697214 / GRB 260213736)
  21. GRB 260211A - SVOM/ECLAIRs refined analysis
  22. GRB 260204A: SVOM/ECLAIRs refined analysis
  23. GRB 260213A: Fermi GBM Final Localization
  24. GRB 260211A: EP-FXT follow-up observation
  25. GRB 260211A: SVOM/VT optical observation
  26. GRB 260212A: Glowbug gamma-ray detection
  27. GRB 260211A: GOTO optical upper limit
  28. Fermi GRB 260212A: Global MASTER-Net observations report
  29. GRB 260212A: Fermi GBM Final Real-time Localization
  30. GRB 260211A: LAST optical upper limit
  31. GRB 260210A: SVOM/GRM observation
  32. Fermi GBM Sub-Threshold Detection of GRB 260211A
  33. Konus-Wind detection of GRB 260207B
  34. GRB 260128B: SVOM/ECLAIRs refined analysis
  35. GRID detection of GRB 260207B
  36. GRB 260211A: LCO optical upper limits
  37. GRB260131A/B: 3.6m DOT Optical Observations
  38. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  39. Fermi trigger No 792537871: Global MASTER-Net observations report
  40. GRB 260211A: SVOM detection of a burst
  41. Swift Operations Update + Community Forum (Friday, February 13 @ 10:00 AM EST)
  42. Konus-Wind detection of GRB 260209B
  43. GRB 260208A: Swift UVOT detection
  44. Konus-Wind detection of GRB 260127B
  45. EP260209a: COLIBRÍ optical upper limit
  46. Fermi GRB 260210C: Global MASTER-Net observations report
  47. EP260209a: LCO optical upper limits
  48. EP260210a: Global MASTER-Net observations report
  49. EP260210a: refined analysis of the EP-FXT observation
  50. EP260209a: Global MASTER-Net observations report
  51. GRB 260208A: LCO detection of the optical counterpart
  52. EP260209a: Einstein Probe detection of a fast X-ray transient
  53. EP260210a: Optical upper limits with Kinder observations
  54. IPN triangulation of GRB 260207B (short/hard with EE)
  55. GRB 260210C: Fermi GBM Final Real-time Localization
  56. GRB 260210A: Glowbug gamma-ray detection
  57. GRB 260210B: Fermi GBM Final Real-time Localization
  58. EP260210a: SVOM/VT optical upper limit
  59. GRB 260210A: AstroSat CZTI detection
  60. GRB 260208C: AstroSat CZTI detection
  61. EP260210a: COLIBRÍ optical upper limit
  62. EP260210a: SVOM/C-GFT upper limit
  63. GRB 260208B: refined analysis of the EP-FXT observation
  64. EP260210a: Einstein Probe detection of an X-ray transient
  65. GRB 260207B: AstroSat CZTI detection
  66. GRB 260208C: SVOM/GRM observation
  67. GRB 260204A: Swift-XRT afterglow detection
  68. GRB 260208B: AstroSat CZTI detection of a bright long burst
  69. GRB260208A: Liverpool Telescope optical follow-up observations
  70. GRB 260208A: Glowbug gamma-ray detection
  71. GRB 260208A: NuSTAR detection of prompt emission
  72. GRB 260208A: Fermi GBM Observation
  73. Fermi GRB 260209A: Global MASTER-Net observations report
  74. GRB 260208B: Swift-XRT observations
  75. GRB 260131A/B: continued Mondy optical observations
  76. GRB 260204A: Swift/UVOT Upper Limits
  77. GRB 260208B: COLIBRÍ optical observations
  78. GRB 260208A: Mondy optical observations (duplicate submission)
  79. GRB 260208A: Mondy optical observations
  80. GRB 260208A: 1.3m DFOT optical detection
  81. GRB 260208A: COLIBRÍ optical observations
  82. GRB 260208B: EP-FXT observation
  83. GRB 260208A: NOT spectroscopic redshift z = 2.36
  84. GRB 260208A: Liverpool Telescope optical detection
  85. Fermi GRB 260208C: Global MASTER-Net observations report
  86. GRB 260208B: SVOM/VT optical candidate
  87. GRB 260208A: GECAM-B observation of a bright burst
  88. GRB 260208A: Zwicky Transient Facility Follow-Up of a Fermi GRB (Trigger 792220053)
  89. GRB 260209A: Fermi GBM Final Real-time Localization
  90. GRB 260208A: SVOM/VT optical observation
  91. Fermi GRB 260208D: Global MASTER-Net observations report
  92. GRB 260208D: Fermi GBM Final Real-time Localization
  93. GRB 260208A: Swift-XRT observations
  94. GRB 260208B: Swift ToO observations
  95. GRB 260208B: SVOM/GRM observation of a bright burst
  96. GRB 260208B: Fermi GBM Detection
  97. LAT GRB 260208B: Global MASTER-Net observations report
  98. GRB 260208B: Fermi-LAT detection
  99. GRB 260208C: Fermi GBM Final Real-time Localization
  100. GRB 260208A: Fermi-LAT detection

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Download all Circulars as a .tar.gz archive (updated once a day):
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