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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"

45718 results found.

  1. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  2. EP260214b: Optical upper limit with Kinder observations
  3. EP260214a: Optical upper limits with Kinder observations
  4. EP260214b: EP-FXT follow-up observation
  5. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  6. EP260214b: DDOTI Optical Detection
  7. EP260214b: GROWTH-India Telescope optical upper limit
  8. EP260214a: VLT near-infrared observation
  9. EP260214b: SVOM/VT optical observation
  10. EP260214a: NOT optical upper limits
  11. EP260214a: COLIBRÍ optical upper limits
  12. EP260214b: OHP/T120 optical observations
  13. EP260214a: refined analysis of the EP-FXT observation
  14. EP260214b: LCO optical counterpart detection
  15. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  16. GRB 260211A: SVOM/VT optical counterpart
  17. EP260214b: COLIBRÍ optical observations
  18. EP260214a: SVOM/VT optical upper limits
  19. EP260214b: NOT optical counterpart detection
  20. EP260214b: Einstein Probe detection of a fast X-ray transient
  21. EP260214a: Global MASTER-Net observations report
  22. EP260214a: Einstein Probe detection of an X-ray transient
  23. GRB 260212A: AstroSat CZTI detection
  24. GRB 260212A: Fermi GBM Observation
  25. EP260213a: Liverpool Telescope optical upper limits
  26. EP260213a: Global MASTER-Net observations report
  27. EP260213a: COLIBRÍ optical upper limits
  28. GRB 260212A: GECAM-B observation
  29. EP260213a: Optical upper limits with Kinder observations
  30. EP260213a: SVOM/VT optical upper limit
  31. EP260213a: Mondy R-band optical upper limit
  32. EP260213a: NUTTelA-TAO Early Optical Limits
  33. EP260213a: SVOM/C-GFT upper limit
  34. EP260213a: refined analysis of the EP-FXT observation
  35. EP260213a: Einstein Probe detection of a fast X-ray transient
  36. EP/WXT 01709258378: NOT optical upper limits
  37. GRB 260212A: SVOM/GRM observation of a long burst
  38. GRB 260213B: Fermi GBM Final Localization
  39. GRB 260213B: BALROG localization (Fermi Trigger 792697214 / GRB 260213736)
  40. GRB 260211A - SVOM/ECLAIRs refined analysis
  41. GRB 260204A: SVOM/ECLAIRs refined analysis
  42. GRB 260213A: Fermi GBM Final Localization
  43. GRB 260211A: EP-FXT follow-up observation
  44. GRB 260211A: SVOM/VT optical observation
  45. GRB 260212A: Glowbug gamma-ray detection
  46. GRB 260211A: GOTO optical upper limit
  47. Fermi GRB 260212A: Global MASTER-Net observations report
  48. GRB 260212A: Fermi GBM Final Real-time Localization
  49. GRB 260211A: LAST optical upper limit
  50. GRB 260210A: SVOM/GRM observation
  51. Fermi GBM Sub-Threshold Detection of GRB 260211A
  52. Konus-Wind detection of GRB 260207B
  53. GRB 260128B: SVOM/ECLAIRs refined analysis
  54. GRID detection of GRB 260207B
  55. GRB 260211A: LCO optical upper limits
  56. GRB260131A/B: 3.6m DOT Optical Observations
  57. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  58. Fermi trigger No 792537871: Global MASTER-Net observations report
  59. GRB 260211A: SVOM detection of a burst
  60. Swift Operations Update + Community Forum (Friday, February 13 @ 10:00 AM EST)
  61. Konus-Wind detection of GRB 260209B
  62. GRB 260208A: Swift UVOT detection
  63. Konus-Wind detection of GRB 260127B
  64. EP260209a: COLIBRÍ optical upper limit
  65. Fermi GRB 260210C: Global MASTER-Net observations report
  66. EP260209a: LCO optical upper limits
  67. EP260210a: Global MASTER-Net observations report
  68. EP260210a: refined analysis of the EP-FXT observation
  69. EP260209a: Global MASTER-Net observations report
  70. GRB 260208A: LCO detection of the optical counterpart
  71. EP260209a: Einstein Probe detection of a fast X-ray transient
  72. EP260210a: Optical upper limits with Kinder observations
  73. IPN triangulation of GRB 260207B (short/hard with EE)
  74. GRB 260210C: Fermi GBM Final Real-time Localization
  75. GRB 260210A: Glowbug gamma-ray detection
  76. GRB 260210B: Fermi GBM Final Real-time Localization
  77. EP260210a: SVOM/VT optical upper limit
  78. GRB 260210A: AstroSat CZTI detection
  79. GRB 260208C: AstroSat CZTI detection
  80. EP260210a: COLIBRÍ optical upper limit
  81. EP260210a: SVOM/C-GFT upper limit
  82. GRB 260208B: refined analysis of the EP-FXT observation
  83. EP260210a: Einstein Probe detection of an X-ray transient
  84. GRB 260207B: AstroSat CZTI detection
  85. GRB 260208C: SVOM/GRM observation
  86. GRB 260204A: Swift-XRT afterglow detection
  87. GRB 260208B: AstroSat CZTI detection of a bright long burst
  88. GRB260208A: Liverpool Telescope optical follow-up observations
  89. GRB 260208A: Glowbug gamma-ray detection
  90. GRB 260208A: NuSTAR detection of prompt emission
  91. GRB 260208A: Fermi GBM Observation
  92. Fermi GRB 260209A: Global MASTER-Net observations report
  93. GRB 260208B: Swift-XRT observations
  94. GRB 260131A/B: continued Mondy optical observations
  95. GRB 260204A: Swift/UVOT Upper Limits
  96. GRB 260208B: COLIBRÍ optical observations
  97. GRB 260208A: Mondy optical observations (duplicate submission)
  98. GRB 260208A: Mondy optical observations
  99. GRB 260208A: 1.3m DFOT optical detection
  100. GRB 260208A: COLIBRÍ optical observations

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