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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"

26517 results found.

  1. EP260302a: SVOM/VT optical observation
  2. EP260306a: Gemini-North redshift z = 4.773
  3. EP260306a: SVOM/VT optical observation
  4. EP260306a: COLIBRÍ optical observations of the fading and red counterpart
  5. EP260306a: Einstein Probe detection of an X-ray transient
  6. EP260302a: Optical afterglow rebrightening
  7. GRB 260228A: further EP-FXT observations and X-ray afterglow confirmation
  8. GRB 260303A: 1.3m DFOT optical upper limit
  9. EP260214b: ATCA 6 GHz observations
  10. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  11. GRB 260303A: SVOM/ECLAIRs refined analysis
  12. GRB 260303B: AstroSat CZTI detection
  13. GRB 260304A: AstroSat CZTI detection of a long burst
  14. SVOM/sb26030408: SVOM detection of an X-ray transient likely associated with Beta Persei
  15. GRB 260303A: SVOM/VT optical observations
  16. GRB 260303A: J-band observations with WINTER
  17. GRB 260303B: NuSTAR detection of prompt emission
  18. IceCube-260217A: No Candidate Transients from the Zwicky Transient Facility
  19. GRB 260228A: SVOM/ECLAIRs refined analysis
  20. GRB 260225A: SVOM/ECLAIRs refined analysis
  21. EP260302a: analysis of the follow-up EP-FXT observation
  22. EP260302a: LCO observations
  23. EP260302a: BOOTES-7 optical counterpart detection at early times
  24. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  25. GRB 260303A: SVOM detection of a burst
  26. GRB 260228A: EP-FXT follow-up observation
  27. EP260302a: Einstein Probe detection of an X-ray transient
  28. GRB 251130B: TERI Gamma-ray detection
  29. GRB 260208A: TERI Gamma-ray detection
  30. GRB 260228A: CAHA 2.2m telescope optical upper limit
  31. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  32. EP260227a: Mephisto optical detection
  33. GRID detection of GRB 260225D
  34. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  35. EP260227a: SVOM/VT optical observation
  36. GRB 260228A: SVOM/VT optical upper limits
  37. GRB 260225D: SVOM/GRM observation
  38. EP260227A: 3.6m DOT optical afterglow detection
  39. GRB 260225B: SVOM/GRM observation
  40. GRB 260228A: SVOM detection of a burst
  41. EP260227a: Liverpool Telescope optical observations
  42. EP260227a: Thai National Telescope observations
  43. EP260227a: Liverpool Telescope observations
  44. EP260227a: COLIBRÍ optical observations
  45. GRB 260225A: SVOM/VT optical continued observations and upper limit
  46. GRID detection of GRB 260223A
  47. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  48. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  49. IceCube cascade alert 142200_1517143 retraction
  50. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  51. Konus-Wind detection of GRB 260226A
  52. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  53. EP260214a: VLT/FORS2 optical observations
  54. GRB 260225A: WINTER J-band upper limit
  55. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  56. GRB 260226A: COLIBRÍ optical upper limits
  57. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  58. GRB 260225D: Glowbug gamma-ray detection of a likely short burst
  59. GRB 260226A: Glowbug gamma-ray detection
  60. GRB 260226A: NuSTAR detection of bright prompt emission
  61. GRB 260226A : GROWTH-India Telescope optical observations
  62. GRB 260226A: LAST optical upper limit
  63. GRB 260226A: Fermi GBM observation
  64. GRB 260226A: Fermi-LAT refined analysis
  65. The EP-WXT trigger 01709258652 is likely a flaring star
  66. GRB 260226A: AstroSat CZTI detection of bright long burst
  67. EP260214a: VLA 6 GHz detection
  68. GRB 260226A: Fermi-LAT detection of a bright burst
  69. GRB260225A: SVOM/ECLAIRs refined position
  70. GRB 260225A: EP-FXT follow-up observation
  71. GRB 260225A: SVOM/VT optical observation
  72. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  73. GRB 260223A: Fermi GBM Observation
  74. GRB 260225A: SVOM/VT optical upper limits
  75. EP260126a: VLA 6 GHz detection
  76. EP260223a: Liverpool Telescope upper limits
  77. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  78. GRB 260225A: SVOM detection of a burst
  79. EP260224a: Einstein Probe detection of an X-ray transient
  80. EP 260225.148: COLIBRÍ Confirmation of flaring star
  81. EP260223a: Xinglong optical upper limit
  82. GRB 260223A: Glowbug gamma-ray detection
  83. EP260213a: Mephisto optical upper limits
  84. EP260223a: EP-FXT follow-up observation
  85. sb26021801: SVOM/VT optical upper limits
  86. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  87. sb26021801: SVOM/C-GFT upper limit
  88. EP260223a: COLIBRÍ optical upper limits
  89. EP260223a: Einstein Probe detection of an X-ray transient
  90. GRB 260223A: SVOM/VT optical observation
  91. GRB 260223A: SVOM/GRM observation
  92. GRB 260223A: COLIBRÍ further optical observations and a brightening
  93. EP260221a: Optical upper limit with Kinder observations
  94. GRB 260223A: COLIBRÍ optical observations
  95. EP260221a: Liverpool Telescope detection of COLIBRÍ counterpart candidate
  96. EP260221a: COLIBRÍ optical counterpart candidate
  97. EP260221a: EP-FXT follow-up observation
  98. EP260221a: Xinglong optical upper limit
  99. ZTF26aaglqak/AT2026dbl: COLIBRÍ Optical Observations
  100. EP260221a: GOTO optical upper limit

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