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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.

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

18333 results found.

  1. EP01709266106 (EP260526a?): Liverpool Telescope upper limits
  2. EP-WXT 01709266106: NOT optical upper limits
  3. Fermi trigger No 801135305: Global MASTER-Net observations report
  4. EP260518a: Einstein Probe detection of an sub-threshold X-ray transient with counterpart AT 2026ndp
  5. GRB 260511A: iTelescope T-75 optical detection
  6. GRB 260520B: SVOM/GRM observation
  7. Konus-Wind detection of GRB 260518A
  8. GRB 260518A: AstroSat CZTI detection of a long burst
  9. GRB 260421B: radio detection with the VLA
  10. GRB 260509A: CrAO ZTSh optical upper limit
  11. GRB 260516D: EP-FXT follow-up observation
  12. GRB 260516D: GOTO optical counterpart detection
  13. GRB 260516D: LCO optical observations
  14. GRB 260515A: further Liverpool Telescope observations
  15. GRB 260516D: SVOM/COLIBRÍ (FM-GFT) optical observations
  16. GRB 260516D: GROWTH-India Telescope optical detection
  17. GRB 260516D: SVOM/VT optical bright candidate
  18. GRB 260515A: CrAO ZTSh BVRI optical observations
  19. Konus-Wind detection of GRB 260515A
  20. GRB 260515A: LCO optical counterpart detection
  21. GRB 260515A: SVOM/COLIBRÍ (FM-GFT) optical observations
  22. GRB 260515A: EP-FXT follow-up observation
  23. EP260514a: refined analysis of the EP-WXT and follow-up EP-FXT observations
  24. EP260514a: NOT optical counterpart confirmation
  25. EP260514a: TRT optical counterpart candidate
  26. EP260514a: SVOM/VT optical candidate
  27. GRB 260515A: OHP/T193 optical observations
  28. EP260514a: COLIBRÍ optical upper limits
  29. GRB 260515A: LCO optical observations
  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. EP260514a: GROWTH-India Telescope optical upper limit
  34. GRB 260511B: GMG Optical Upper Limit
  35. EP260514a: Einstein Probe detection of a fast X-ray transient
  36. EP260512a: LCO optical upper limits
  37. GRB 260511B: Mephisto multi-band optical followup
  38. The EP-WXT trigger 01709262077 is likely a flaring star
  39. EP260512a: EP-FXT follow-up observation
  40. EP260507a: Xinglong Schmidt optical counterpart detection
  41. GRB 260511B: further SAO RAS optical observations
  42. The EP-WXT trigger 01709262036 is likely a flaring star
  43. EP260512a: COLIBRÍ optical upper limits
  44. EP260512a: Einstein Probe detection of an X-ray transient
  45. GRB 260511B: further J-band observations by the SYSU 80 cm infrared telescope
  46. GRB 260511B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  47. GRB 260509A: Infrared J and Hs observations with MDM/MIRAGE
  48. GRB 260510C: Infrared J and Hs detections with MDM/MIRAGE
  49. EP260507a: Infrared J and Hs upper limits with MDM/MIRAGE
  50. GRB 260511B: SAO RAS optical observations
  51. GRB 260511B: FRAM-ORM optical detection
  52. GRB 260511A: EP-FXT follow-up observation
  53. GRB 260511B: EP-FXT follow-up observation
  54. GRB 260511B: LCO optical counterpart detection
  55. GRB260511B: MAO/AZT-22 optical observations
  56. GRB 260511B: LCO optical observations
  57. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) further optical observations
  58. GRB 260511B: SVOM/COLIBRÍ (FM-GFT) optical observations
  59. GRB 260510B: EP-FXT follow-up observation
  60. GRB 260509A: SAO RAS optical observations
  61. GRB 260511A: REM near-infrared detection
  62. GRB 260511B: GROWTH-India Telescope optical observations
  63. GRB 260511B: J-band observations by the SYSU 80 cm infrared telescope
  64. GRB 260511B: SVOM/VT optical observation with VHF data
  65. GRB 260511B: TRT optical observation
  66. GRB 260511B : MITSuME Akeno optical afterglow candidate detection
  67. GRB 260511A: Fermi GBM Detection
  68. GRB 260511B SVOM/C-GFT optical counterpart detection
  69. EP260509a: LCO optical upper limits
  70. GRB 260511A: UTGO H50 optical afterglow observation
  71. GRB 260511B: SVOM detection of a burst
  72. GRB 260510C: EP-FXT follow-up observation
  73. GRB 260510C: SVOM/VT optical counterpart confirmation
  74. EP260509a: EP-FXT non-detection and upper limit
  75. GRB 260511A: SVOM/VT optical observation with VHF data
  76. GRB 260511A: KAIT optical afterglow observations
  77. GRB 260511A: LCO optical afterglow detection
  78. GRB 260511A: SVOM/COLIBRÍ (FM-GFT) optical counterpart
  79. GRB 260511A: TRT optical counterpart detection
  80. GRB 260511A: SVOM detection of a bright burst
  81. GRB 260510C: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  82. GRB 260510C: SVOM detection of a burst
  83. GRB 260510B: LCO optical upper limits
  84. EP260509a: Einstein Probe detection of an X-ray transient
  85. GRB 260509A: Liverpool Telescope optical observations
  86. GRB 260510B: SVOM detection of a burst
  87. GRB 260509A: LCO optical observations
  88. GRB 260509A: KAIT optical observations
  89. GRB 260509A: SVOM/COLIBRÍ (FM-GFT) observations
  90. GRB 260509A: SVOM/VT optical candidate with VHF data
  91. GRB 260509A: LCO optical counterpart detection
  92. GRB 260509A: SVOM detection of a burst
  93. EP260507a: REM optical/NIR observations
  94. EP260507a: refined analysis of the EP-WXT and EP-FXT observations
  95. EP260507a: COLIBRÍ optical observations
  96. EP260507a: NOT optical observations
  97. EP260507a: further Liverpool Telescope observations
  98. EP260507a: Liverpool Telescope optical upper limits
  99. EP260507a: TRT optical counterpart detection
  100. EP260507a: Kinder optical counterpart candidate

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