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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').
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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"

36159 results found.

  1. GRB 260516D: GOTO optical counterpart detection
  2. GRB 260516D: LCO optical observations
  3. GRB 260515A: further Liverpool Telescope observations
  4. GRB 260516D: SVOM/COLIBRÍ (FM-GFT) optical observations
  5. GRB 260516D: GTC/OSIRIS+ spectroscopic redshift z = 1.801
  6. GRB 260516D: GROWTH-India Telescope optical detection
  7. GRB 260516D: SVOM/VT optical bright candidate
  8. GRB 260516D: FRAM-ORM optical limit
  9. GRB 260515A: CrAO ZTSh BVRI optical observations
  10. Fermi GRB 260516C: Global MASTER-Net observations report
  11. GRB 260516D: SVOM possible detection of a burst
  12. GRB 260516C: Fermi GBM Final Real-time Localization
  13. Konus-Wind detection of GRB 260515A
  14. GRB 260515A: Liverpool Telescope optical detection
  15. GRB 260515A: LCO optical counterpart detection
  16. Fermi Gamma-ray Burst Monitor trigger 800627191/260516518 is not a GRB
  17. GRB 260515A: SVOM/COLIBRÍ (FM-GFT) optical observations
  18. GRB 260515A: EP-FXT follow-up observation
  19. Fermi GRB 260516B: Global MASTER-Net observations report
  20. GRB 260516B: Fermi GBM Final Real-time Localization
  21. Fermi Gamma-ray Burst Monitor trigger 800592653/260516119 is not a GRB
  22. GRB 260515A: SVOM/VT optical observations
  23. GRB 260515A: OHP/T193 optical observations
  24. GRB 260516A: Fermi GBM Final Real-time Localization
  25. GRID detection of GRB 260507A
  26. GRB 260515A: GTC/OSIRIS+ spectroscopic redshift z = 0.764
  27. GRB 260515A: LCO optical observations
  28. SVOM GRB 260515A: Global MASTER-Net observations report
  29. GRB 260515A: NOT optical observations.
  30. SVOM GRB 260515A: MASTER OT J151044.43+243321.7 optical counterpart detection
  31. GRB 260515A: SVOM/VT optical candidate from VHF data
  32. GRB 260515A: JinShan optical counterpart candidate
  33. GRB 260515A: SVOM detection of a burst
  34. GRB 260510C: Glowbug gamma-ray detection
  35. GRB 260511B: NOT optical observations
  36. Konus-Wind detection of GRB 260512A
  37. GRB 260510C: CALET Gamma-Ray Burst Monitor detection
  38. GRB 260511B: GMG Optical Upper Limit
  39. IPN triangulation of GRB 260512A
  40. GRB 260511B: Mephisto multi-band optical followup
  41. Fermi GRB 260514A: Global MASTER-Net observations report
  42. GRB 260512A: AstroSat CZTI detection
  43. GRB 260514A: Fermi GBM Final Real-time Localization
  44. Fermi GRB 260513A: Global MASTER-Net observations report
  45. Fermi GRB 260512A: Global MASTER-Net observations report
  46. GRB 260511B: further SAO RAS optical observations
  47. GRB 260513A: Fermi GBM Final Real-time Localization
  48. GRB 260509A: SVOM/VT optical observations
  49. Konus-Wind detection of GRB 260511B
  50. GRB 260511B: further J-band observations by the SYSU 80 cm infrared telescope
  51. GRB 260511B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  52. GRB 260512A: NuSTAR detection of prompt emission
  53. GRB 260509A: Infrared J and Hs observations with MDM/MIRAGE
  54. GRB 260510C: Infrared J and Hs detections with MDM/MIRAGE
  55. EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
  56. GRB 260512A: Fermi GBM Final Real-time Localization
  57. GRB 260511A: Glowbug gamma-ray detection
  58. Konus-Wind detection of GRB 260511A
  59. MASS-Cube (GRID 2.0) detection of GRB 260511A
  60. MASS-Cube (GRID 2.0) detection of GRB 260507A
  61. GRB 260511B: SAO RAS optical observations
  62. GRB 260510D: Glowbug gamma-ray detection of a likely short burst
  63. GRB 260511B: FRAM-ORM optical detection
  64. GRB 260511A: EP-FXT follow-up observation
  65. GRB 260511B: EP-FXT follow-up observation
  66. GRB 260511B: LCO optical counterpart detection
  67. GRB260511B: MAO/AZT-22 optical observations
  68. GRB 260511A: SVOM/VT optical observations
  69. GRB 260511B: LCO optical observations
  70. GRB 260511B: OHP/T193 spectroscopic observations
  71. GRB 260511B: GOTO optical counterpart detection
  72. GRB 260511B: Xinglong 2.16m/BEFOSC redshift confirmation
  73. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) further optical observations
  74. GRB 260510A: AstroSat CZTI detection (Erroneous Submission)
  75. GRB 260511B: SVOM/VT optical observations
  76. GRB 260511B: SVOM/COLIBRÍ (FM-GFT) optical observations
  77. GRB 260510B: EP-FXT follow-up observation
  78. GRB 260511B: OSIRIS+/GTC redshift z=2.006
  79. GRB 260510C: Fermi GBM Observation
  80. GRB 260509A: SAO RAS optical observations
  81. GRB 260511A: REM near-infrared detection
  82. GRB 260511B: GROWTH-India Telescope optical observations
  83. GRB 260511B: AstroSat CZTI detection
  84. GRB 260506B: Glowbug gamma-ray detection
  85. GRB 260506A: Glowbug gamma-ray detection of a short burst
  86. GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
  87. GRB 260511B: NuSTAR detection of prompt emission
  88. GRB 260511A: NuSTAR detection of prompt emission
  89. GRB 260511B: Fermi GBM Detection
  90. GRB 260511C: Fermi GBM Final Real-time Localization
  91. GRB 260511B: SVOM/VT optical observation with VHF data
  92. GRB 260511B: TRT optical observation
  93. GRB 260510B: SVOM/ECLAIRs refined analysis
  94. GRB 260511B : MITSuME Akeno optical afterglow candidate detection
  95. GRB 260511A: Fermi GBM Detection
  96. GRB 260511B SVOM/C-GFT optical counterpart detection
  97. GRB 260511A: UTGO H50 optical afterglow observation
  98. GRB 260510C: AstroSat CZTI detection
  99. GRB 260511B: SVOM detection of a burst
  100. GRB 260511B: Fermi GBM Final Real-time Localization

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