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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"

32552 results found.

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

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