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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"

32495 results found.

  1. EP260901a: Global MASTER-Net observations report
  2. IceCube-260827A: No transient candidates from the Zwicky Transient Facility
  3. GRB 260831B / sb26083106: SVOM/GWAC-F60A/B confirmation of optical variation of nova V* GK Per
  4. GRB 260831B / sb26083106: SVOM/VT optical variability of V* GK Per
  5. NuSTAR Transient 260828: LCO Optical Upper Limits
  6. SVOM trigger sb26083106 is not a GRB
  7. GRB 260829A: AstroSat CZTI detection
  8. GRB 260831B: EP-FXT follow-up observation
  9. GRB 260830A: NuSTAR detection of prompt emission
  10. GRB 260831B: LCO optical upper limits
  11. EP260830a: Global MASTER-Net observations report
  12. GRB 260827A: SVOM/GRM observation
  13. IPN triangulation of GRB 260829A
  14. GRB 260827A: Glowbug gamma-ray detection
  15. EP260727a: ATCA 10 GHz detection
  16. Fermi-LAT Gamma-ray Observations of IceCube-260827A
  17. Fermi-LAT Gamma-ray Observations of IceCube-260825A
  18. GRB 260829A: GECAM-B observation of a long burst
  19. GRB 260825A: SVOM/GRM observation of a long burst
  20. GRB 260825A: GECAM-B observation
  21. GRB 260829A: Fermi GBM Detection
  22. GRB 260825A: AstroSat CZTI detection
  23. IceCube-260827A: Upper limits from a search for additional neutrino events in IceCube
  24. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  25. IceCube-260825A: Upper limits from a search for additional neutrino events in IceCube
  26. GRB 260818B: Further EP-FXT observation
  27. GRB 260818B: VLT optical and nIR observations
  28. GRB 260818B: TNG NIR observations
  29. IceCube-260827A - IceCube observation of a high-energy neutrino candidate track-like event
  30. GRB 260818B: 6 GHz VLA observations
  31. GRB 260818B: SVOM/VT optical upper limit and continuous observations
  32. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  33. GRB 260808B: SAO RAS observations of the optical rebrightening
  34. EP260822a: Global MASTER-Net observations report
  35. IceCube-260825A: No transient candidates from the Zwicky Transient Facility
  36. GRB 260807A: EP-FXT follow-up observations
  37. GRB 260822A: SVOM/ECLAIRs refined analysis
  38. GRB 260809A: SVOM/ECLAIRs refined analysis
  39. GRB 260822A: SVOM/VT optical upper limits
  40. IceCube-260825A - IceCube observation of a high-energy neutrino candidate track-like event
  41. GRB 260822A: PRIME near-infrared upper limits from multiple epochs
  42. GRB 260822A: EP/FXT follow-up observations
  43. GRB 260822A: the candidate optical afterglow is an unrelated type-Ia SN
  44. GRB 260818A: further EP-FXT observations and X-ray afterglow confirmation
  45. EP260822a: EP-FXT non-detection and upper limit
  46. GRB 260822A: Retraction of GOTO optical counterpart detection GCN 45431
  47. GRB 260822A: GOTO optical counterpart detection
  48. GRB 260822A: SVOM/VT optical detection of COLIBRÍ candidate
  49. GRB 260822A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  50. GRB 260822A: LCO optical upper limits
  51. GRB 260822A: GROWTH-India Telescope Upper Limits
  52. GRB 260822A: GOTO optical upper limit
  53. Fermi-LAT Gamma-ray Observations of IceCube-260821A
  54. Fermi-LAT Gamma-ray Observations of IceCube-260807A
  55. IceCube-260821A: Upper limits from a search for additional neutrino events in IceCube
  56. GRB 260818B: VLA radio observations
  57. GRB 260818B: SVOM/C-GFT optical upper limit
  58. EP260731a: SVOM/ECLAIRs detection through offline targeted search
  59. GRB 260820A: Insight-HXMT/HE detection
  60. IceCube-260821A - IceCube observation of a high-energy neutrino candidate track-like event
  61. GRB 260818B: SVOM/GRM observation
  62. GRB 260818B: Insight-HXMT detection
  63. GRB 260818B: EP-FXT follow-up observation
  64. GRB 260818A: J-band observations with WINTER
  65. GRB 260818B: SVOM/ECLAIRs refined analysis
  66. GRB 260818A: SVOM/ECLAIRs refined analysis
  67. GRB 260818B: NOT optical upper limits
  68. GRB 260810A: SVOM/GRM observation
  69. GRB 260818B: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  70. GRB260818A: EP-FXT follow-up observation
  71. GRB 260818B: LCO optical upper limits
  72. EP260806a: SAO RAS multicolor optical observations
  73. GRB 260818A: LCO optical upper limits
  74. EP260812a: AbAO optical upper limit
  75. GRB 260818A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  76. GRB 260810A: Insight-HXMT/HE detection
  77. EP260806a: SVOM/ECLAIRs detection through targeted search
  78. EP260806a: NUTTELA-TAO optical observations
  79. EP260812a: AZT-22 optical upper limit
  80. EP260812b: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.034
  81. EP260806a: WFST optical observations
  82. EP260812b: Optical upper limit with Kinder
  83. GRB 260805D: SVOM/GRM detection of a possible magnetar burst
  84. GRB 260808B: Liverpool Telescope further optical observations
  85. GRB 260808B: GTC/OSIRIS+ spectroscopic redshift z = 1.295
  86. EP260812a: NOT and Liverpool Telescope upper limits:
  87. EP260812b: Liverpool Telescope observations
  88. EP260812b: GOTO detection of the optical counterpart
  89. EP260812a: refined analysis of the EP-WXT and autonomous EP-FXT observation
  90. EP260812a: SVOM/C-GFT optical upper limit
  91. EP260812b: COLIBRÍ optical observations
  92. EP260812b: SVOM/VT optical observation
  93. GRB 260808A: SVOM/GRM observation
  94. EP260812b: Einstein Probe detection of an X-ray transient
  95. Fermi GBM Sub-Threshold Detection of GRB 260809A
  96. GRB 260810A: Glowbug gamma-ray detection
  97. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical rebrightening
  98. GRB 260809A: SAO RAS optical observations
  99. GRB 260808B: SAO RAS optical observations
  100. GRB 260808B: SVOM/VT optical re-brightening at day 3

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