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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

27318 results found.

  1. EP260512a: LCO optical upper limits
  2. GRB 260511B: Mephisto multi-band optical followup
  3. Fermi GRB 260514A: Global MASTER-Net observations report
  4. GRB 260512A: AstroSat CZTI detection
  5. EP260512a: EP-FXT follow-up observation
  6. EP260507a: Xinglong Schmidt optical counterpart detection
  7. EP260512a: Global MASTER-Net observations report
  8. Fermi GRB 260513A: Global MASTER-Net observations report
  9. Fermi GRB 260512A: Global MASTER-Net observations report
  10. GRB 260511B: further SAO RAS optical observations
  11. GRB 260509A: SVOM/VT optical observations
  12. The EP-WXT trigger 01709262036 is likely a flaring star
  13. EP260512a: COLIBRÍ optical upper limits
  14. EP260512a: Einstein Probe detection of an X-ray transient
  15. GRB 260511B: further J-band observations by the SYSU 80 cm infrared telescope
  16. GRB 260511B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  17. GRB 260512A: NuSTAR detection of prompt emission
  18. GRB 260509A: Infrared J and Hs observations with MDM/MIRAGE
  19. GRB 260510C: Infrared J and Hs detections with MDM/MIRAGE
  20. EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
  21. GRB 260511A: Glowbug gamma-ray detection
  22. GRB 260511B: SAO RAS optical observations
  23. GRB 260510D: Glowbug gamma-ray detection of a likely short burst
  24. GRB 260511B: FRAM-ORM optical detection
  25. GRB 260511A: EP-FXT follow-up observation
  26. GRB 260511B: EP-FXT follow-up observation
  27. GRB 260511B: LCO optical counterpart detection
  28. GRB260511B: MAO/AZT-22 optical observations
  29. GRB 260511B: LCO optical observations
  30. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) further optical observations
  31. GRB 260511B: SVOM/COLIBRÍ (FM-GFT) optical observations
  32. GRB 260510B: EP-FXT follow-up observation
  33. GRB 260510C: Fermi GBM Observation
  34. GRB 260509A: SAO RAS optical observations
  35. GRB 260511A: REM near-infrared detection
  36. GRB 260511B: GROWTH-India Telescope optical observations
  37. GRB 260506B: Glowbug gamma-ray detection
  38. GRB 260506A: Glowbug gamma-ray detection of a short burst
  39. GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
  40. GRB 260511B: NuSTAR detection of prompt emission
  41. GRB 260511A: NuSTAR detection of prompt emission
  42. GRB 260511B: Fermi GBM Detection
  43. GRB 260511B: SVOM/VT optical observation with VHF data
  44. GRB 260511B: TRT optical observation
  45. GRB 260511B : MITSuME Akeno optical afterglow candidate detection
  46. GRB 260511A: Fermi GBM Detection
  47. GRB 260511B SVOM/C-GFT optical counterpart detection
  48. EP260509a: LCO optical upper limits
  49. GRB 260511A: UTGO H50 optical afterglow observation
  50. GRB 260511B: SVOM detection of a burst
  51. GRB 260510C: EP-FXT follow-up observation
  52. EP260509a: EP-FXT non-detection and upper limit
  53. GRB 260511A: SVOM/VT optical observation with VHF data
  54. Fermi GRB 260511A: Global MASTER-Net observations report
  55. GRB 260511A: KAIT optical afterglow observations
  56. GRB 260511A: LCO optical afterglow detection
  57. GRB 260511A: SVOM/COLIBRÍ (FM-GFT) optical counterpart
  58. GRB 260511A: TRT optical counterpart detection
  59. GRB 260511A: SVOM detection of a bright burst
  60. GRB 260511A: BALROG localization (Fermi Trigger 800172815 / GRB 260511259)
  61. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  62. GRB 260510C: MAXI/GSC detection
  63. EP260509a: Global MASTER-Net observations report
  64. Fermi GBM Sub-Threshold Detection of GRB 260510B
  65. GRB 260510C: SVOM detection of a burst
  66. GRB 260510B: LCO optical upper limits
  67. EP260509a: Einstein Probe detection of an X-ray transient
  68. GRB 260509A: Liverpool Telescope optical observations
  69. GRB 260510B: SVOM detection of a burst
  70. GRB 260509A: LCO optical observations
  71. SVOM GRB 260509A: MASTER-OAFA optical observation
  72. Fermi GRB 260510A: Global MASTER-Net observations report
  73. GRB 260509A: KAIT optical observations
  74. GRB 260509A: SVOM/COLIBRÍ (FM-GFT) observations
  75. GRB 260509A: SVOM/VT optical candidate with VHF data
  76. GRB 260509A: LCO optical counterpart detection
  77. GRB 260509A: SVOM detection of a burst
  78. IceCube-260504A: Upper limits from a search for additional neutrino events in IceCube
  79. EP260507a: REM optical/NIR observations
  80. EP260507a: refined analysis of the EP-WXT and EP-FXT observations
  81. GRB 260507B / EP260507a: Fermi-GBM Sub-Threshold Detection
  82. EP260507a: COLIBRÍ optical observations
  83. EP260507a: NOT optical observations
  84. EP260507a: further Liverpool Telescope observations
  85. EP260507a: Liverpool Telescope optical upper limits
  86. EP260507a: TRT optical counterpart detection
  87. EP260507a: Kinder optical counterpart candidate
  88. EP260507a: LCO optical counterpart
  89. EP260507a: Einstein Probe detection of an X-ray transient
  90. GRB 260506B: BALROG localization (Fermi Trigger 799765648 / GRB 260506547)
  91. Fermi GRB 260506A: Global MASTER-Net observations report
  92. IceCube Alert 260505A: Global MASTER-Net observations report
  93. GRB 260430B: Glowbug gamma-ray detection
  94. GRB 260421B: radio observation with the VLA
  95. Fermi-LAT Gamma-ray Observations of IceCube-260504A
  96. GRB 260430B: AstroSat CZTI detection of a long burst
  97. GRB 260502A: SVOM/GRM observation of a short GRB
  98. GRB 260503A: SVOM/GRM observation of a GRB
  99. Konus-Wind detection of GRB 260411C
  100. GRB 260504B: REM optical/NIR observations

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