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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

28056 results found.

  1. GRB 251113A: TERI Gamma-ray detection
  2. GRB 260428A: TERI Gamma-ray detection
  3. GRB 260519C: NuSTAR detection of prompt emission
  4. Konus-Wind detection of GRB 260518A
  5. GRB 260516D: SVOM/ECLAIRs refined analysis
  6. GRB 260421B: radio detection with the VLA
  7. GRB 260509A: CrAO ZTSh optical upper limit
  8. GRB 260516D: GOTO optical counterpart detection
  9. GRB 260516D: LCO optical observations
  10. GRB 260515A: further Liverpool Telescope observations
  11. GRB 260516D: SVOM/COLIBRÍ (FM-GFT) optical observations
  12. GRB 260516D: GROWTH-India Telescope optical detection
  13. GRB 260516D: SVOM/VT optical bright candidate
  14. GRB 260515A: CrAO ZTSh BVRI optical observations
  15. Fermi GRB 260516C: Global MASTER-Net observations report
  16. SVOM GRB260516D: Global MASTER-Net observations report
  17. GRB 260516D: SVOM possible detection of a burst
  18. GRB 260515A: LCO optical counterpart detection
  19. GRB 260515A: SVOM/COLIBRÍ (FM-GFT) optical observations
  20. EP260514a: refined analysis of the EP-WXT and follow-up EP-FXT observations
  21. EP260514a: NOT optical counterpart confirmation
  22. EP260514a: TRT optical counterpart candidate
  23. EP260514a: SVOM/VT optical candidate
  24. Fermi GRB 260516B: Global MASTER-Net observations report
  25. GRB 260515A: OHP/T193 optical observations
  26. EP260514a: COLIBRÍ optical upper limits
  27. GRB 260515A: LCO optical observations
  28. SVOM GRB 260515A: Global MASTER-Net observations report
  29. SVOM GRB 260515A: MASTER OT J151044.43+243321.7 optical counterpart detection
  30. GRB 260515A: SVOM/VT optical candidate from VHF data
  31. GRB 260515A: JinShan optical counterpart candidate
  32. GRB 260515A: SVOM detection of a burst
  33. GRB 260510C: Glowbug gamma-ray detection
  34. EP260514a: GROWTH-India Telescope optical upper limit
  35. GRB 260511B: GMG Optical Upper Limit
  36. EP260514a: Global MASTER-Net observations report
  37. EP260514a: Einstein Probe detection of a fast X-ray transient
  38. EP260512a: LCO optical upper limits
  39. GRB 260511B: Mephisto multi-band optical followup
  40. Fermi GRB 260514A: Global MASTER-Net observations report
  41. GRB 260512A: AstroSat CZTI detection
  42. EP260512a: EP-FXT follow-up observation
  43. EP260507a: Xinglong Schmidt optical counterpart detection
  44. EP260512a: Global MASTER-Net observations report
  45. Fermi GRB 260513A: Global MASTER-Net observations report
  46. Fermi GRB 260512A: Global MASTER-Net observations report
  47. GRB 260511B: further SAO RAS optical observations
  48. GRB 260509A: SVOM/VT optical observations
  49. The EP-WXT trigger 01709262036 is likely a flaring star
  50. EP260512a: COLIBRÍ optical upper limits
  51. EP260512a: Einstein Probe detection of an X-ray transient
  52. GRB 260511B: further J-band observations by the SYSU 80 cm infrared telescope
  53. GRB 260511B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  54. GRB 260512A: NuSTAR detection of prompt emission
  55. GRB 260509A: Infrared J and Hs observations with MDM/MIRAGE
  56. GRB 260510C: Infrared J and Hs detections with MDM/MIRAGE
  57. EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
  58. GRB 260511A: Glowbug gamma-ray detection
  59. GRB 260511B: SAO RAS optical observations
  60. GRB 260510D: Glowbug gamma-ray detection of a likely short burst
  61. GRB 260511B: FRAM-ORM optical detection
  62. GRB 260511A: EP-FXT follow-up observation
  63. GRB 260511B: EP-FXT follow-up observation
  64. GRB 260511B: LCO optical counterpart detection
  65. GRB260511B: MAO/AZT-22 optical observations
  66. GRB 260511B: LCO optical observations
  67. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) further optical observations
  68. GRB 260511B: SVOM/COLIBRÍ (FM-GFT) optical observations
  69. GRB 260510B: EP-FXT follow-up observation
  70. GRB 260510C: Fermi GBM Observation
  71. GRB 260509A: SAO RAS optical observations
  72. GRB 260511A: REM near-infrared detection
  73. GRB 260511B: GROWTH-India Telescope optical observations
  74. GRB 260506B: Glowbug gamma-ray detection
  75. GRB 260506A: Glowbug gamma-ray detection of a short burst
  76. GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
  77. GRB 260511B: NuSTAR detection of prompt emission
  78. GRB 260511A: NuSTAR detection of prompt emission
  79. GRB 260511B: Fermi GBM Detection
  80. GRB 260511B: SVOM/VT optical observation with VHF data
  81. GRB 260511B: TRT optical observation
  82. GRB 260511B : MITSuME Akeno optical afterglow candidate detection
  83. GRB 260511A: Fermi GBM Detection
  84. GRB 260511B SVOM/C-GFT optical counterpart detection
  85. EP260509a: LCO optical upper limits
  86. GRB 260511A: UTGO H50 optical afterglow observation
  87. GRB 260511B: SVOM detection of a burst
  88. GRB 260510C: EP-FXT follow-up observation
  89. EP260509a: EP-FXT non-detection and upper limit
  90. GRB 260511A: SVOM/VT optical observation with VHF data
  91. Fermi GRB 260511A: Global MASTER-Net observations report
  92. GRB 260511A: KAIT optical afterglow observations
  93. GRB 260511A: LCO optical afterglow detection
  94. GRB 260511A: SVOM/COLIBRÍ (FM-GFT) optical counterpart
  95. GRB 260511A: TRT optical counterpart detection
  96. GRB 260511A: SVOM detection of a bright burst
  97. GRB 260511A: BALROG localization (Fermi Trigger 800172815 / GRB 260511259)
  98. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  99. GRB 260510C: MAXI/GSC detection
  100. EP260509a: Global MASTER-Net observations report

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