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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"

38620 results found.

  1. GRB 260310B: Fermi GBM Final Real-time Localization
  2. GRB 260307B: SVOM/ECLAIRs refined analysis
  3. GRB 260208A: radio detection with the VLA
  4. GRB 260310A: Fermi GBM Final Real-time Localization
  5. GRB 260307A: Glowbug gamma-ray detection
  6. GRB 260308A: Fermi GBM Final Real-time Localization
  7. Fermi GBM Sub-Threshold Detection of GRB 260307B
  8. GRB 260307B: Mephisto optical upper limits
  9. GRB 260307B: possible NOT optical counterpart
  10. GRB 260307B: SVOM/VT upper limit with X band data analysis
  11. GRB260307B: GROWTH-India Telescope optical upper limit
  12. GRB 260307B: SVOM/VT optical candidate
  13. GRB 260307B: SVOM/C-GFT upper limit
  14. GRB 260307B: SVOM detection of a burst
  15. GRB 260307A: Fermi GBM Final Localization
  16. GRB 260211A: late-time NOT i-band observations consistent with archival flux
  17. EP260306a: refined analysis of the EP-WXT and EP-FXT observations
  18. EP260302a: SVOM/VT optical observation
  19. EP260306a: Gemini-North redshift z = 4.773
  20. EP260306a: SVOM/VT optical observation
  21. EP260302a: Gemini-South redshift z = 1.535
  22. EP260306a: COLIBRÍ optical observations of the fading and red counterpart
  23. EP260306a: Einstein Probe detection of an X-ray transient
  24. EP260302a: Optical afterglow rebrightening
  25. GRB 260228A: further EP-FXT observations and X-ray afterglow confirmation
  26. GRB 260303A: 1.3m DFOT optical upper limit
  27. EP260214b: ATCA 6 GHz observations
  28. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  29. GRB 260303A: SVOM/ECLAIRs refined analysis
  30. GRB 260305A: Fermi GBM Final Real-time Localization
  31. GRB 260303B: AstroSat CZTI detection
  32. GRB 260304A: AstroSat CZTI detection of a long burst
  33. SVOM/sb26030408: SVOM detection of an X-ray transient likely associated with Beta Persei
  34. GRB 260303A: SVOM/VT optical observations
  35. GRB 260303B: NuSTAR detection of prompt emission
  36. IceCube-260217A: No Candidate Transients from the Zwicky Transient Facility
  37. GRB 260228A: SVOM/ECLAIRs refined analysis
  38. GRB 260225A: SVOM/ECLAIRs refined analysis
  39. GRB 260303B: BALROG localization (Fermi Trigger 794237065 / GRB 260303559)
  40. GRB 260303B: Fermi GBM Final Real-time Localization
  41. EP260302a: analysis of the follow-up EP-FXT observation
  42. EP260227a: Gemini-South optical observations
  43. EP260302a: LCO observations
  44. EP260302a: BOOTES-7 optical counterpart detection at early times
  45. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  46. GRB 260303A: SVOM detection of a burst
  47. GRB 260228A: EP-FXT follow-up observation
  48. EP260302a: Einstein Probe detection of an X-ray transient
  49. GRB 251130B: TERI Gamma-ray detection
  50. GRB 260208A: TERI Gamma-ray detection
  51. GRB 260302A: Fermi GBM Final Real-time Localization
  52. EP260227a: Mondy optical observations
  53. GRB 260228A: CAHA 2.2m telescope optical upper limit
  54. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  55. EP260227a: Mephisto optical detection
  56. GRID detection of GRB 260225D
  57. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  58. EP260227a: further LCO observations
  59. EP260227a: SVOM/VT optical observation
  60. GRB 260228A: SVOM/VT optical upper limits
  61. GRB 260225D: SVOM/GRM observation
  62. EP260227A: 3.6m DOT optical afterglow detection
  63. GRB 260225B: SVOM/GRM observation
  64. GRB 260228A: SVOM detection of a burst
  65. EP260227a: Liverpool Telescope optical observations
  66. EP260227a: LCOGT Optical Observations
  67. GRB 260226A: Asiago r-band upper limit
  68. EP260227a: Thai National Telescope observations
  69. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  70. EP260227a: Liverpool Telescope observations
  71. EP260227a: COLIBRÍ optical observations
  72. EP260227a: NOT optical observations
  73. GRB 260225A: SVOM/VT optical continued observations and upper limit
  74. GRID detection of GRB 260223A
  75. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  76. EP/WXT trigger 01709258681 (EP260227a?): LCO candidate afterglow
  77. IceCube cascade alert 142200_1517143 retraction
  78. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  79. Konus-Wind detection of GRB 260226A
  80. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  81. EP260214a: VLT/FORS2 optical observations
  82. GRB 260225A: WINTER J-band upper limit
  83. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  84. GRB 260226A: COLIBRÍ optical upper limits
  85. GRB 260226A: LCOGT Optical Upper Limit
  86. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  87. GRB 260225D: Glowbug gamma-ray detection of a likely short burst
  88. GRB 260226A: Glowbug gamma-ray detection
  89. GRB 260226A: NuSTAR detection of bright prompt emission
  90. GRB 260226A : GROWTH-India Telescope optical observations
  91. GRB 260226A: LAST optical upper limit
  92. GRB 260226A: Fermi GBM observation
  93. GRB 260226A: Fermi-LAT refined analysis
  94. The EP-WXT trigger 01709258652 is likely a flaring star
  95. GRB 260226A: AstroSat CZTI detection of bright long burst
  96. EP260214a: VLA 6 GHz detection
  97. GRB 260226A: Fermi-LAT detection of a bright burst
  98. GRB 260226A???: BALROG localization (Fermi Trigger 793795080 / GRB 260226443)
  99. EP260224a: LCO optical upper limits
  100. GRB260225A: SVOM/ECLAIRs refined position

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