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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"

32756 results found.

  1. EP260214b: LCO optical counterpart detection
  2. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  3. GRB 260211A: SVOM/VT optical counterpart
  4. EP260214b: COLIBRÍ optical observations
  5. EP260214a: SVOM/VT optical upper limits
  6. EP260214b: NOT optical counterpart detection
  7. EP260214a: Global MASTER-Net observations report
  8. GRB 260212A: AstroSat CZTI detection
  9. GRB 260212A: Fermi GBM Observation
  10. EP260213a: Liverpool Telescope optical upper limits
  11. EP260213a: Global MASTER-Net observations report
  12. EP260213a: COLIBRÍ optical upper limits
  13. GRB 260212A: GECAM-B observation
  14. EP260213a: Optical upper limits with Kinder observations
  15. EP260213a: SVOM/VT optical upper limit
  16. EP260213a: Mondy R-band optical upper limit
  17. EP260213a: NUTTelA-TAO Early Optical Limits
  18. EP260213a: SVOM/C-GFT upper limit
  19. EP260213a: refined analysis of the EP-FXT observation
  20. GRB 260212A: SVOM/GRM observation of a long burst
  21. GRB 260211A - SVOM/ECLAIRs refined analysis
  22. GRB 260204A: SVOM/ECLAIRs refined analysis
  23. GRB 260211A: EP-FXT follow-up observation
  24. GRB 260211A: SVOM/VT optical observation
  25. GRB 260212A: Glowbug gamma-ray detection
  26. GRB 260211A: GOTO optical upper limit
  27. Fermi GRB 260212A: Global MASTER-Net observations report
  28. GRB 260211A: LAST optical upper limit
  29. GRB 260210A: SVOM/GRM observation
  30. Fermi GBM Sub-Threshold Detection of GRB 260211A
  31. Konus-Wind detection of GRB 260207B
  32. GRB 260128B: SVOM/ECLAIRs refined analysis
  33. GRID detection of GRB 260207B
  34. GRB 260211A: LCO optical upper limits
  35. GRB260131A/B: 3.6m DOT Optical Observations
  36. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  37. GRB 260208A: Swift UVOT detection
  38. Konus-Wind detection of GRB 260127B
  39. EP260209a: COLIBRÍ optical upper limit
  40. Fermi GRB 260210C: Global MASTER-Net observations report
  41. EP260209a: LCO optical upper limits
  42. EP260210a: Global MASTER-Net observations report
  43. EP260210a: refined analysis of the EP-FXT observation
  44. EP260209a: Global MASTER-Net observations report
  45. GRB 260208A: LCO detection of the optical counterpart
  46. EP260210a: Optical upper limits with Kinder observations
  47. IPN triangulation of GRB 260207B (short/hard with EE)
  48. GRB 260210A: Glowbug gamma-ray detection
  49. EP260210a: SVOM/VT optical upper limit
  50. GRB 260210A: AstroSat CZTI detection
  51. GRB 260208C: AstroSat CZTI detection
  52. EP260210a: COLIBRÍ optical upper limit
  53. EP260210a: SVOM/C-GFT upper limit
  54. GRB 260208B: refined analysis of the EP-FXT observation
  55. GRB 260207B: AstroSat CZTI detection
  56. GRB 260208C: SVOM/GRM observation
  57. GRB 260204A: Swift-XRT afterglow detection
  58. GRB 260208B: AstroSat CZTI detection of a bright long burst
  59. GRB260208A: Liverpool Telescope optical follow-up observations
  60. GRB 260208A: Glowbug gamma-ray detection
  61. GRB 260208A: NuSTAR detection of prompt emission
  62. GRB 260208A: Fermi GBM Observation
  63. Fermi GRB 260209A: Global MASTER-Net observations report
  64. GRB 260208B: Swift-XRT observations
  65. GRB 260131A/B: continued Mondy optical observations
  66. GRB 260204A: Swift/UVOT Upper Limits
  67. GRB 260208B: COLIBRÍ optical observations
  68. GRB 260208A: Mondy optical observations (duplicate submission)
  69. GRB 260208A: Mondy optical observations
  70. GRB 260208A: 1.3m DFOT optical detection
  71. GRB 260208A: COLIBRÍ optical observations
  72. GRB 260208B: EP-FXT observation
  73. GRB 260208A: NOT spectroscopic redshift z = 2.36
  74. GRB 260208A: Liverpool Telescope optical detection
  75. Fermi GRB 260208C: Global MASTER-Net observations report
  76. GRB 260208B: SVOM/VT optical candidate
  77. GRB 260208A: GECAM-B observation of a bright burst
  78. GRB 260208A: Zwicky Transient Facility Follow-Up of a Fermi GRB (Trigger 792220053)
  79. GRB 260208A: SVOM/VT optical observation
  80. Fermi GRB 260208D: Global MASTER-Net observations report
  81. GRB 260208A: Swift-XRT observations
  82. GRB 260208B: Swift ToO observations
  83. GRB 260208B: SVOM/GRM observation of a bright burst
  84. GRB 260208B: Fermi GBM Detection
  85. GRB 260208B: Fermi-LAT detection
  86. GRB 260208A: Fermi-LAT detection
  87. GRB 260207B: GECAM-B observation
  88. GRB 260208A: Swift ToO observations
  89. GRB 260208A: Fermi GBM Classification Correction
  90. GRB 260208A: GOTO detection of a potential optical counterpart (GOTO26aob)
  91. GRB 260208A : MASTER bright optical transient inside retracted Fermi error-box
  92. Fermi GRB 260208A: Global MASTER-Net observations report
  93. GRB 260207A : MASTER optical counterpart discovery
  94. GRB 260131A/B: Mondy and Terskol optical observations
  95. Fermi GRB 260207B: Global MASTER-Net observations report
  96. GRB 260206A: Swift-XRT observations
  97. EP260131a: VLA detection
  98. GRB 260206A: Tiled Swift observations
  99. GRB 260204A: SVOM/VT confirms fading of the optical afterglow
  100. GRB 260204A: Swift-XRT observations

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