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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"

32722 results found.

  1. Retraction of GCN 43965: GRB is actually solar flare
  2. GRB 260131A/B: radio detection with the VLA
  3. EP260302a: MeerKAT radio counterpart
  4. GRB260307A: GECAM-B observation of a burst
  5. GRB 260308A: SVOM/GRM observation of a short GRB
  6. EP260306a: Mondy optical upper limit
  7. GRB 260310A: AstroSat CZTI detection of a long burst
  8. Fermi GRB 260310B: Global MASTER-Net observations report
  9. Fermi GRB 260310A: Global MASTER-Net observations report
  10. GRB 260307B: SVOM/ECLAIRs refined analysis
  11. GRB 260208A: radio detection with the VLA
  12. GRB 260307A: Glowbug gamma-ray detection
  13. Fermi GBM Sub-Threshold Detection of GRB 260307B
  14. GRB 260307B: Mephisto optical upper limits
  15. GRB 260307B: possible NOT optical counterpart
  16. GRB 260307B: SVOM/VT upper limit with X band data analysis
  17. Fermi GRB 260307A: Global MASTER-Net observations report
  18. GRB260307B: GROWTH-India Telescope optical upper limit
  19. GRB 260307B: SVOM/VT optical candidate
  20. GRB 260307B: SVOM/C-GFT upper limit
  21. GRB 260211A: late-time NOT i-band observations consistent with archival flux
  22. EP260306a: refined analysis of the EP-WXT and EP-FXT observations
  23. GRB 260207A: TESS Detection and Possible VLA Counterpart
  24. EP260302a: SVOM/VT optical observation
  25. EP260306a: Gemini-North redshift z = 4.773
  26. EP260306a: SVOM/VT optical observation
  27. EP260302a: Gemini-South redshift z = 1.535
  28. EP260306a: COLIBRÍ optical observations of the fading and red counterpart
  29. EP260306a: Einstein Probe detection of an X-ray transient
  30. EP260302a: Optical afterglow rebrightening
  31. GRB 260228A: further EP-FXT observations and X-ray afterglow confirmation
  32. GRB 260303A: 1.3m DFOT optical upper limit (duplicate submission)
  33. GRB 260303A: 1.3m DFOT optical upper limit
  34. EP260214b: ATCA 6 GHz observations
  35. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  36. GRB 260303A: SVOM/ECLAIRs refined analysis
  37. Fermi GRB 260305A: Global MASTER-Net observations report
  38. GRB 260303B: AstroSat CZTI detection
  39. GRB 260303A: SVOM/VT optical observations
  40. GRB 260303A: J-band observations with WINTER
  41. GRB 260303B: NuSTAR detection of prompt emission
  42. EP260302a: Global MASTER-Net observations report
  43. Fermi GRB 260303B: Global MASTER-Net observations report
  44. IceCube-260217A: No Candidate Transients from the Zwicky Transient Facility
  45. GRB 260228A: SVOM/ECLAIRs refined analysis
  46. GRB 260225A: SVOM/ECLAIRs refined analysis
  47. EP260302a: analysis of the follow-up EP-FXT observation
  48. EP260227a: Gemini-South optical observations
  49. EP260302a: LCO observations
  50. EP260302a: BOOTES-7 optical counterpart detection at early times
  51. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  52. GRB 260228A: EP-FXT follow-up observation
  53. GRB 251130B: TERI Gamma-ray detection
  54. GRB 260208A: TERI Gamma-ray detection
  55. EP260227a: Mondy optical observations
  56. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  57. EP260227a: Mephisto optical detection
  58. GRID detection of GRB 260225D
  59. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  60. EP260227a: further LCO observations
  61. EP260227a: SVOM/VT optical observation
  62. GRB 260228A: SVOM/VT optical upper limits
  63. GRB 260225D: SVOM/GRM observation
  64. EP260227A: 3.6m DOT optical afterglow detection
  65. GRB 260225B: SVOM/GRM observation
  66. EP260227a: FTW optical and NIR observations
  67. EP260227a: Liverpool Telescope optical observations
  68. EP260227a: LCOGT Optical Observations
  69. GRB 260226A: Asiago r-band upper limit
  70. EP260227a: Thai National Telescope observations
  71. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  72. EP260227a: Liverpool Telescope observations
  73. EP260227a: COLIBRÍ optical observations
  74. EP260227a: NOT optical observations
  75. GRB 260225A: SVOM/VT optical continued observations and upper limit
  76. GRID detection of GRB 260223A
  77. EP260227a: Global MASTER-Net observations report
  78. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  79. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  80. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  81. Konus-Wind detection of GRB 260226A
  82. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  83. EP260214a: VLT/FORS2 optical observations
  84. GRB 260225A: WINTER J-band upper limit
  85. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  86. GRB 260226A: COLIBRÍ optical upper limits
  87. GRB 260226A: LCOGT Optical Upper Limit
  88. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  89. GRB 260226A: Glowbug gamma-ray detection
  90. GRB 260226A: NuSTAR detection of bright prompt emission
  91. GRB 260226A : GROWTH-India Telescope optical observations
  92. GRB 260226A: LAST optical upper limit
  93. GRB 260226A: Fermi GBM observation
  94. GRB 260226A: Fermi-LAT refined analysis
  95. Fermi GRB 260226A: Global MASTER-Net observations report
  96. GRB 260226A: AstroSat CZTI detection of bright long burst
  97. EP260214a: VLA 6 GHz detection
  98. GRB 260226A: Fermi-LAT detection of a bright burst
  99. EP260224a: LCO optical upper limits
  100. GRB260225A: SVOM/ECLAIRs refined position

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