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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

28207 results found.

  1. GRB 260303A: 1.3m DFOT optical upper limit
  2. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  3. GRB 260305A: Fermi GBM Final Real-time Localization
  4. GRB 260303B: AstroSat CZTI detection
  5. GRB 260304A: AstroSat CZTI detection of a long burst
  6. SVOM/sb26030408: SVOM detection of an X-ray transient likely associated with Beta Persei
  7. GRB 260303A: SVOM/VT optical observations
  8. GRB 260303B: NuSTAR detection of prompt emission
  9. GRB 260303B: Fermi GBM Final Real-time Localization
  10. EP260302a: BOOTES-7 optical counterpart detection at early times
  11. GRB 260303A: SVOM detection of a burst
  12. EP260302a: Einstein Probe detection of an X-ray transient
  13. GRB 251130B: TERI Gamma-ray detection
  14. GRB 260208A: TERI Gamma-ray detection
  15. GRB 260302A: Fermi GBM Final Real-time Localization
  16. GRB 260228A: CAHA 2.2m telescope optical upper limit
  17. EP260227a: Mephisto optical detection
  18. GRID detection of GRB 260225D
  19. EP260227A: 3.6m DOT optical afterglow detection
  20. GRB 260228A: SVOM detection of a burst
  21. GRB 260226A: Asiago r-band upper limit
  22. EP260227a: Liverpool Telescope observations
  23. GRID detection of GRB 260223A
  24. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  25. EP/WXT trigger 01709258681 (EP260227a?): LCO candidate afterglow
  26. IceCube cascade alert 142200_1517143 retraction
  27. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  28. Konus-Wind detection of GRB 260226A
  29. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  30. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  31. GRB 260225D: Glowbug gamma-ray detection of a likely short burst
  32. GRB 260226A: Glowbug gamma-ray detection
  33. GRB 260226A: NuSTAR detection of bright prompt emission
  34. GRB 260226A: AstroSat CZTI detection of bright long burst
  35. EP260214a: VLA 6 GHz detection
  36. GRB 260226A: Fermi-LAT detection of a bright burst
  37. GRB 260226A: Fermi GBM Final Real-time Localization
  38. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  39. GRB 260225C: Fermi GBM Final Real-time Localization
  40. GRB 260225A: SVOM/VT optical upper limits
  41. GRB 260225B: Fermi GBM Final Real-time Localization
  42. EP260126a: VLA 6 GHz detection
  43. EP260223a: Liverpool Telescope upper limits
  44. GRB 260225A: SVOM detection of a burst
  45. EP260224a: Einstein Probe detection of an X-ray transient
  46. EP260223a: Xinglong optical upper limit
  47. GRB 260223A: Glowbug gamma-ray detection
  48. EP260213a: Mephisto optical upper limits
  49. EP260223a: EP-FXT follow-up observation
  50. sb26021801: SVOM/VT optical upper limits
  51. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  52. EP260223a: Einstein Probe detection of an X-ray transient
  53. EP260221a: Optical upper limit with Kinder observations
  54. GRB 260223A: Fermi GBM Final Real-time Localization
  55. EP260221a: Liverpool Telescope detection of COLIBRÍ counterpart candidate
  56. EP260221a: COLIBRÍ optical counterpart candidate
  57. EP260221a: Gemini South z-band upper limit
  58. GRB 260222A: Fermi GBM Final Real-time Localization
  59. GRB 260221B: Fermi GBM Final Real-time Localization
  60. EP-WXT01709258519: Xinglong optical upper limit
  61. EP260221a: Xinglong optical upper limit
  62. GRB 260221A: Fermi GBM Final Real-time Localization
  63. EP260221a: Einstein Probe detection of an X-ray transient
  64. GRB 260219A: AstroSat CZTI detection
  65. GRB 260219A: Fermi GBM Final Real-time Localization
  66. GRB 260217A: Fermi GBM Final Localization
  67. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  68. sb26021801: SVOM detection of a long faint X-ray transient
  69. EP260214b: 1.3m DFOT optical upper limit
  70. Konus-Wind detection of GRB 260212A
  71. IPN triangulation of GRB 260212A
  72. IceCube-260217A - IceCube observation of a high-energy neutrino candidate track-like event
  73. GRB 260216A: Fermi GBM Final Real-time Localization
  74. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  75. EP260214b: Optical upper limit with Kinder observations
  76. EP260214a: Optical upper limits with Kinder observations
  77. EP260214b: EP-FXT follow-up observation
  78. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  79. EP260214b: DDOTI Optical Detection
  80. EP260214b: LCO optical counterpart detection
  81. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  82. EP260214b: NOT optical counterpart detection
  83. EP260214b: Einstein Probe detection of a fast X-ray transient
  84. EP260214a: Einstein Probe detection of an X-ray transient
  85. GRB 260212A: AstroSat CZTI detection
  86. EP260213a: Liverpool Telescope optical upper limits
  87. EP260213a: Optical upper limits with Kinder observations
  88. EP260213a: Einstein Probe detection of a fast X-ray transient
  89. GRB 260213B: Fermi GBM Final Localization
  90. GRB 260204A: SVOM/ECLAIRs refined analysis
  91. GRB 260213A: Fermi GBM Final Localization
  92. GRB 260212A: Glowbug gamma-ray detection
  93. GRB 260212A: Fermi GBM Final Real-time Localization
  94. Fermi GBM Sub-Threshold Detection of GRB 260211A
  95. Konus-Wind detection of GRB 260207B
  96. GRID detection of GRB 260207B
  97. GRB260131A/B: 3.6m DOT Optical Observations
  98. GRB 260211A: SVOM detection of a burst
  99. Swift Operations Update + Community Forum (Friday, February 13 @ 10:00 AM EST)
  100. Konus-Wind detection of GRB 260209B

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