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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"

36187 results found.

  1. GRB 260221A: Fermi GBM Final Real-time Localization
  2. GRB 260219A: AstroSat CZTI detection
  3. GRB 260219A: GECAM-B observation of a long burst
  4. Fermi GRB 260219A: Global MASTER-Net observations report
  5. GRB 260219A: Fermi GBM Final Real-time Localization
  6. GRB 260217A: Fermi GBM Final Localization
  7. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  8. EP260214b: Mondy optical observations
  9. EP260210a: Mondy optical upper limits
  10. Konus-Wind detection of GRB 260212A
  11. GRB 260208A: AbAO and Terskol optical upper limits
  12. GRB 260208A: continued Mondy optical observations
  13. IPN triangulation of GRB 260212A
  14. GRB 260213A: GECAM-B observation of a short burst
  15. GRB 260216A: Fermi Gamma-ray Burst Monitor trigger 792969362/260216886 is not a GRB
  16. GRB 260216A: Fermi GBM Final Real-time Localization
  17. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  18. EP260214a: Optical upper limits with Kinder observations
  19. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  20. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  21. GRB 260211A: SVOM/VT optical counterpart
  22. GRB 260212A: AstroSat CZTI detection
  23. GRB 260212A: Fermi GBM Observation
  24. GRB 260212A: GECAM-B observation
  25. EP260213a: Mondy R-band optical upper limit
  26. GRB 260212A: SVOM/GRM observation of a long burst
  27. GRB 260213B: Fermi GBM Final Localization
  28. GRB 260213B: BALROG localization (Fermi Trigger 792697214 / GRB 260213736)
  29. GRB 260211A - SVOM/ECLAIRs refined analysis
  30. GRB 260204A: SVOM/ECLAIRs refined analysis
  31. GRB 260213A: Fermi GBM Final Localization
  32. GRB 260211A: EP-FXT follow-up observation
  33. GRB 260211A: SVOM/VT optical observation
  34. GRB 260212A: Glowbug gamma-ray detection
  35. GRB 260211A: GOTO optical upper limit
  36. Fermi GRB 260212A: Global MASTER-Net observations report
  37. GRB 260212A: Fermi GBM Final Real-time Localization
  38. GRB 260211A: LAST optical upper limit
  39. GRB 260210A: SVOM/GRM observation
  40. Fermi GBM Sub-Threshold Detection of GRB 260211A
  41. Konus-Wind detection of GRB 260207B
  42. GRB 260128B: SVOM/ECLAIRs refined analysis
  43. GRID detection of GRB 260207B
  44. GRB 260211A: LCO optical upper limits
  45. GRB260131A/B: 3.6m DOT Optical Observations
  46. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  47. GRB 260211A: SVOM detection of a burst
  48. Konus-Wind detection of GRB 260209B
  49. GRB 260208A: Swift UVOT detection
  50. Konus-Wind detection of GRB 260127B
  51. Fermi GRB 260210C: Global MASTER-Net observations report
  52. GRB 260208A: LCO detection of the optical counterpart
  53. IPN triangulation of GRB 260207B (short/hard with EE)
  54. GRB 260210C: Fermi GBM Final Real-time Localization
  55. GRB 260210A: Glowbug gamma-ray detection
  56. GRB 260210B: Fermi GBM Final Real-time Localization
  57. GRB 260210A: AstroSat CZTI detection
  58. GRB 260208C: AstroSat CZTI detection
  59. GRB 260208B: refined analysis of the EP-FXT observation
  60. GRB 260207B: AstroSat CZTI detection
  61. GRB 260208C: SVOM/GRM observation
  62. GRB 260204A: Swift-XRT afterglow detection
  63. GRB 260208B: AstroSat CZTI detection of a bright long burst
  64. GRB 260208A: Glowbug gamma-ray detection
  65. GRB 260208A: NuSTAR detection of prompt emission
  66. GRB 260208A: Fermi GBM Observation
  67. Fermi GRB 260209A: Global MASTER-Net observations report
  68. GRB 260208B: Swift-XRT observations
  69. GRB 260131A/B: continued Mondy optical observations
  70. GRB 260204A: Swift/UVOT Upper Limits
  71. GRB 260208B: COLIBRÍ optical observations
  72. GRB 260208A: Mondy optical observations (duplicate submission)
  73. GRB 260208A: Mondy optical observations
  74. GRB 260208A: 1.3m DFOT optical detection
  75. GRB 260208A: COLIBRÍ optical observations
  76. GRB 260208B: EP-FXT observation
  77. GRB 260208A: NOT spectroscopic redshift z = 2.36
  78. GRB 260208A: Liverpool Telescope optical detection
  79. Fermi GRB 260208C: Global MASTER-Net observations report
  80. GRB 260208B: SVOM/VT optical candidate
  81. GRB 260208A: GECAM-B observation of a bright burst
  82. GRB 260208A: Zwicky Transient Facility Follow-Up of a Fermi GRB (Trigger 792220053)
  83. GRB 260209A: Fermi GBM Final Real-time Localization
  84. GRB 260208A: SVOM/VT optical observation
  85. Fermi GRB 260208D: Global MASTER-Net observations report
  86. GRB 260208D: Fermi GBM Final Real-time Localization
  87. GRB 260208A: Swift-XRT observations
  88. GRB 260208B: Swift ToO observations
  89. GRB 260208B: SVOM/GRM observation of a bright burst
  90. GRB 260208B: Fermi GBM Detection
  91. LAT GRB 260208B: Global MASTER-Net observations report
  92. GRB 260208B: Fermi-LAT detection
  93. GRB 260208C: Fermi GBM Final Real-time Localization
  94. GRB 260208A: Fermi-LAT detection
  95. GRB 260207B: GECAM-B observation
  96. GRB 260208A: Swift ToO observations
  97. GRB 260208A: Fermi GBM Classification Correction
  98. GRB 260208A: GOTO detection of a potential optical counterpart (GOTO26aob)
  99. GRB 260208A : MASTER bright optical transient inside retracted Fermi error-box
  100. GRB 260208B: BALROG localization (Fermi Trigger 792237169 / GRB 260208412)

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