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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"

37576 results found.

  1. GRB 260527A/EP260527a: Gemini GMOS-S Optical Observations
  2. EP260527a / GRB 260527A: VLT detection of the optical and nIR counterpart
  3. EP260527a / GRB 260527A: NOT optical observations
  4. GRB 260527A/EP260527a: FTW optical and NIR observations
  5. EP260527a/GRB 260527A: Infrared J upper limit with MDM/MIRAGE
  6. GRB 260527A: CALET Gamma-Ray Burst Monitor detection
  7. EP260527a/GRB 260527A: EP-FXT follow-up observation
  8. GRB 260527A: GECAM-B detection of a short burst probably associated with EP260527a
  9. GRB 260526A: GECAM-B observation
  10. Konus-Wind detection of GRB 260527A (short/hard) ~4 min before EP260527a
  11. Fermi trigger No 801580882: Global MASTER-Net observations report
  12. GRB 260524A: SVOM/ECLAIRs detection of a burst through on-ground search
  13. GRB 260525A: AstroSat CZTI detection
  14. Fermi GRB 260526A: Global MASTER-Net observations report
  15. GRB 260526A: Fermi GBM Final Real-time Localization
  16. Fermi GRB 260525A: Global MASTER-Net observations report
  17. GRB 260525A: Fermi GBM Final Real-time Localization
  18. GRB 260523B: AstroSat CZTI detection
  19. GRB 260523B: GECAM-B observation
  20. Fermi GRB 260523A: Global MASTER-Net observations report
  21. GRB 260523B: Fermi GBM Final Real-time Localization
  22. GRB 260523A: Fermi GBM Final Real-time Localization
  23. GRB 260522A: Fermi GBM Observation
  24. GRB 260522B: NuSTAR detection of prompt emission
  25. GRB 260522B: Fermi GBM Final Real-time Localization
  26. GRB 260522A: GOTO optical upper limit
  27. Fermi trigger No 801135305: Global MASTER-Net observations report
  28. Fermi GRB 260522A: Global MASTER-Net observations report
  29. GRB 260522A: Fermi-LAT detection
  30. GRB 260519C: SVOM/GRM observation
  31. GRB 260522A: Fermi GBM Final Real-time Localization
  32. GRB 260511A: iTelescope T-75 optical detection
  33. GRB 260520B: SVOM/GRM observation
  34. GRB 260411B: TERI Gamma-ray detection
  35. GRB 260407A: TERI Gamma-ray detection
  36. GRB 260307A: TERI Gamma-ray detection
  37. GRB 260225D: TERI Gamma-ray detection
  38. GRB 251118A: TERI Gamma-ray detection
  39. GRB 251113A: TERI Gamma-ray detection
  40. GRB 260428A: TERI Gamma-ray detection
  41. Konus-Wind detection of GRB 260519C
  42. GRB 260520B: Fermi GBM Final Localization
  43. GRB 260509A: SVOM/ECLAIRs refined analysis
  44. GRB 260520A: Fermi GBM Final Localization
  45. GRB 260519D: Fermi GBM Final Localization Correction
  46. GRB 260519C: NuSTAR detection of prompt emission
  47. Konus-Wind detection of GRB 260518A
  48. GRB 260519B: Fermi GBM Final Localization
  49. GRB 260519A: Fermi GBM Final Localization
  50. GRB 260518A: AstroSat CZTI detection of a long burst
  51. GRB 260516D: SVOM/ECLAIRs refined analysis
  52. GRB 260515A: SVOM/ECLAIRs refined analysis
  53. GRB 260421B: radio detection with the VLA
  54. GRID detection of GRB 260511A
  55. GRB 260509A: CrAO ZTSh optical upper limit (Duplicate Submission)
  56. GRB 260509A: CrAO ZTSh optical upper limit
  57. GRB 260516D: EP-FXT follow-up observation
  58. GRB 260516D: GOTO optical counterpart detection
  59. GRB 260516D: LCO optical observations
  60. GRB 260515A: further Liverpool Telescope observations
  61. GRB 260516D: SVOM/COLIBRÍ (FM-GFT) optical observations
  62. GRB 260516D: GTC/OSIRIS+ spectroscopic redshift z = 1.801
  63. GRB 260516D: GROWTH-India Telescope optical detection
  64. GRB 260516D: SVOM/VT optical bright candidate
  65. GRB 260516D: FRAM-ORM optical limit
  66. GRB 260515A: CrAO ZTSh BVRI optical observations
  67. Fermi GRB 260516C: Global MASTER-Net observations report
  68. GRB 260516D: SVOM possible detection of a burst
  69. GRB 260516C: Fermi GBM Final Real-time Localization
  70. Konus-Wind detection of GRB 260515A
  71. GRB 260515A: Liverpool Telescope optical detection
  72. GRB 260515A: LCO optical counterpart detection
  73. Fermi Gamma-ray Burst Monitor trigger 800627191/260516518 is not a GRB
  74. GRB 260515A: SVOM/COLIBRÍ (FM-GFT) optical observations
  75. GRB 260515A: EP-FXT follow-up observation
  76. Fermi GRB 260516B: Global MASTER-Net observations report
  77. GRB 260516B: Fermi GBM Final Real-time Localization
  78. Fermi Gamma-ray Burst Monitor trigger 800592653/260516119 is not a GRB
  79. GRB 260515A: SVOM/VT optical observations
  80. GRB 260515A: OHP/T193 optical observations
  81. GRB 260516A: Fermi GBM Final Real-time Localization
  82. GRID detection of GRB 260507A
  83. GRB 260515A: GTC/OSIRIS+ spectroscopic redshift z = 0.764
  84. GRB 260515A: LCO optical observations
  85. SVOM GRB 260515A: Global MASTER-Net observations report
  86. GRB 260515A: NOT optical observations.
  87. SVOM GRB 260515A: MASTER OT J151044.43+243321.7 optical counterpart detection
  88. GRB 260515A: SVOM/VT optical candidate from VHF data
  89. GRB 260515A: JinShan optical counterpart candidate
  90. GRB 260515A: SVOM detection of a burst
  91. GRB 260510C: Glowbug gamma-ray detection
  92. GRB 260511B: NOT optical observations
  93. Konus-Wind detection of GRB 260512A
  94. GRB 260510C: CALET Gamma-Ray Burst Monitor detection
  95. GRB 260511B: GMG Optical Upper Limit
  96. IPN triangulation of GRB 260512A
  97. GRB 260511B: Mephisto multi-band optical followup
  98. Fermi GRB 260514A: Global MASTER-Net observations report
  99. GRB 260512A: AstroSat CZTI detection
  100. GRB 260514A: Fermi GBM Final Real-time Localization

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