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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"

32751 results found.

  1. EP260214b: NOT optical counterpart detection
  2. EP260214a: Global MASTER-Net observations report
  3. GRB 260212A: AstroSat CZTI detection
  4. GRB 260212A: Fermi GBM Observation
  5. EP260213a: Liverpool Telescope optical upper limits
  6. EP260213a: Global MASTER-Net observations report
  7. EP260213a: COLIBRÍ optical upper limits
  8. GRB 260212A: GECAM-B observation
  9. EP260213a: Optical upper limits with Kinder observations
  10. EP260213a: SVOM/VT optical upper limit
  11. EP260213a: Mondy R-band optical upper limit
  12. EP260213a: NUTTelA-TAO Early Optical Limits
  13. EP260213a: SVOM/C-GFT upper limit
  14. EP260213a: refined analysis of the EP-FXT observation
  15. GRB 260212A: SVOM/GRM observation of a long burst
  16. GRB 260211A - SVOM/ECLAIRs refined analysis
  17. GRB 260204A: SVOM/ECLAIRs refined analysis
  18. GRB 260211A: EP-FXT follow-up observation
  19. GRB 260211A: SVOM/VT optical observation
  20. GRB 260212A: Glowbug gamma-ray detection
  21. GRB 260211A: GOTO optical upper limit
  22. Fermi GRB 260212A: Global MASTER-Net observations report
  23. GRB 260211A: LAST optical upper limit
  24. GRB 260210A: SVOM/GRM observation
  25. Fermi GBM Sub-Threshold Detection of GRB 260211A
  26. Konus-Wind detection of GRB 260207B
  27. GRB 260128B: SVOM/ECLAIRs refined analysis
  28. GRID detection of GRB 260207B
  29. GRB 260211A: LCO optical upper limits
  30. GRB260131A/B: 3.6m DOT Optical Observations
  31. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  32. GRB 260208A: Swift UVOT detection
  33. Konus-Wind detection of GRB 260127B
  34. EP260209a: COLIBRÍ optical upper limit
  35. Fermi GRB 260210C: Global MASTER-Net observations report
  36. EP260209a: LCO optical upper limits
  37. EP260210a: Global MASTER-Net observations report
  38. EP260210a: refined analysis of the EP-FXT observation
  39. EP260209a: Global MASTER-Net observations report
  40. GRB 260208A: LCO detection of the optical counterpart
  41. EP260210a: Optical upper limits with Kinder observations
  42. IPN triangulation of GRB 260207B (short/hard with EE)
  43. GRB 260210A: Glowbug gamma-ray detection
  44. EP260210a: SVOM/VT optical upper limit
  45. GRB 260210A: AstroSat CZTI detection
  46. GRB 260208C: AstroSat CZTI detection
  47. EP260210a: COLIBRÍ optical upper limit
  48. EP260210a: SVOM/C-GFT upper limit
  49. GRB 260208B: refined analysis of the EP-FXT observation
  50. GRB 260207B: AstroSat CZTI detection
  51. GRB 260208C: SVOM/GRM observation
  52. GRB 260204A: Swift-XRT afterglow detection
  53. GRB 260208B: AstroSat CZTI detection of a bright long burst
  54. GRB260208A: Liverpool Telescope optical follow-up observations
  55. GRB 260208A: Glowbug gamma-ray detection
  56. GRB 260208A: NuSTAR detection of prompt emission
  57. GRB 260208A: Fermi GBM Observation
  58. Fermi GRB 260209A: Global MASTER-Net observations report
  59. GRB 260208B: Swift-XRT observations
  60. GRB 260131A/B: continued Mondy optical observations
  61. GRB 260204A: Swift/UVOT Upper Limits
  62. GRB 260208B: COLIBRÍ optical observations
  63. GRB 260208A: Mondy optical observations (duplicate submission)
  64. GRB 260208A: Mondy optical observations
  65. GRB 260208A: 1.3m DFOT optical detection
  66. GRB 260208A: COLIBRÍ optical observations
  67. GRB 260208B: EP-FXT observation
  68. GRB 260208A: NOT spectroscopic redshift z = 2.36
  69. GRB 260208A: Liverpool Telescope optical detection
  70. Fermi GRB 260208C: Global MASTER-Net observations report
  71. GRB 260208B: SVOM/VT optical candidate
  72. GRB 260208A: GECAM-B observation of a bright burst
  73. GRB 260208A: Zwicky Transient Facility Follow-Up of a Fermi GRB (Trigger 792220053)
  74. GRB 260208A: SVOM/VT optical observation
  75. Fermi GRB 260208D: Global MASTER-Net observations report
  76. GRB 260208A: Swift-XRT observations
  77. GRB 260208B: Swift ToO observations
  78. GRB 260208B: SVOM/GRM observation of a bright burst
  79. GRB 260208B: Fermi GBM Detection
  80. GRB 260208B: Fermi-LAT detection
  81. GRB 260208A: Fermi-LAT detection
  82. GRB 260207B: GECAM-B observation
  83. GRB 260208A: Swift ToO observations
  84. GRB 260208A: Fermi GBM Classification Correction
  85. GRB 260208A: GOTO detection of a potential optical counterpart (GOTO26aob)
  86. GRB 260208A : MASTER bright optical transient inside retracted Fermi error-box
  87. Fermi GRB 260208A: Global MASTER-Net observations report
  88. GRB 260207A : MASTER optical counterpart discovery
  89. GRB 260131A/B: Mondy and Terskol optical observations
  90. Fermi GRB 260207B: Global MASTER-Net observations report
  91. GRB 260206A: Swift-XRT observations
  92. EP260131a: VLA detection
  93. GRB 260206A: Tiled Swift observations
  94. GRB 260204A: SVOM/VT confirms fading of the optical afterglow
  95. GRB 260204A: Swift-XRT observations
  96. GRB 260204A: LCO optical afterglow detection
  97. GRB 260204A: SVOM/VT optical candidate
  98. GRB 260204A : MASTER Global robotic net optical observations
  99. Fermi GBM Sub-Threshold Detection of GRB 260204A
  100. GRB 260204A: GOTO optical upper limit

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