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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"

32711 results found.

  1. Fermi GBM Sub-Threshold Detection of GRB 260307B
  2. GRB 260307B: Mephisto optical upper limits
  3. GRB 260307B: possible NOT optical counterpart
  4. GRB 260307B: SVOM/VT upper limit with X band data analysis
  5. Fermi GRB 260307A: Global MASTER-Net observations report
  6. GRB260307B: GROWTH-India Telescope optical upper limit
  7. GRB 260307B: SVOM/VT optical candidate
  8. GRB 260307B: SVOM/C-GFT upper limit
  9. GRB 260211A: late-time NOT i-band observations consistent with archival flux
  10. EP260306a: refined analysis of the EP-WXT and EP-FXT observations
  11. GRB 260207A: TESS Detection and Possible VLA Counterpart
  12. EP260302a: SVOM/VT optical observation
  13. EP260306a: Gemini-North redshift z = 4.773
  14. EP260306a: SVOM/VT optical observation
  15. EP260302a: Gemini-South redshift z = 1.535
  16. EP260306a: COLIBRÍ optical observations of the fading and red counterpart
  17. EP260306a: Einstein Probe detection of an X-ray transient
  18. EP260302a: Optical afterglow rebrightening
  19. GRB 260228A: further EP-FXT observations and X-ray afterglow confirmation
  20. GRB 260303A: 1.3m DFOT optical upper limit (duplicate submission)
  21. GRB 260303A: 1.3m DFOT optical upper limit
  22. EP260214b: ATCA 6 GHz observations
  23. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  24. GRB 260303A: SVOM/ECLAIRs refined analysis
  25. Fermi GRB 260305A: Global MASTER-Net observations report
  26. GRB 260303B: AstroSat CZTI detection
  27. GRB 260303A: SVOM/VT optical observations
  28. GRB 260303A: J-band observations with WINTER
  29. GRB 260303B: NuSTAR detection of prompt emission
  30. EP260302a: Global MASTER-Net observations report
  31. Fermi GRB 260303B: Global MASTER-Net observations report
  32. IceCube-260217A: No Candidate Transients from the Zwicky Transient Facility
  33. GRB 260228A: SVOM/ECLAIRs refined analysis
  34. GRB 260225A: SVOM/ECLAIRs refined analysis
  35. EP260302a: analysis of the follow-up EP-FXT observation
  36. EP260227a: Gemini-South optical observations
  37. EP260302a: LCO observations
  38. EP260302a: BOOTES-7 optical counterpart detection at early times
  39. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  40. GRB 260228A: EP-FXT follow-up observation
  41. GRB 251130B: TERI Gamma-ray detection
  42. GRB 260208A: TERI Gamma-ray detection
  43. EP260227a: Mondy optical observations
  44. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  45. EP260227a: Mephisto optical detection
  46. GRID detection of GRB 260225D
  47. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  48. EP260227a: further LCO observations
  49. EP260227a: SVOM/VT optical observation
  50. GRB 260228A: SVOM/VT optical upper limits
  51. GRB 260225D: SVOM/GRM observation
  52. EP260227A: 3.6m DOT optical afterglow detection
  53. GRB 260225B: SVOM/GRM observation
  54. EP260227a: FTW optical and NIR observations
  55. EP260227a: Liverpool Telescope optical observations
  56. EP260227a: LCOGT Optical Observations
  57. GRB 260226A: Asiago r-band upper limit
  58. EP260227a: Thai National Telescope observations
  59. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  60. EP260227a: Liverpool Telescope observations
  61. EP260227a: COLIBRÍ optical observations
  62. EP260227a: NOT optical observations
  63. GRB 260225A: SVOM/VT optical continued observations and upper limit
  64. GRID detection of GRB 260223A
  65. EP260227a: Global MASTER-Net observations report
  66. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  67. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  68. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  69. Konus-Wind detection of GRB 260226A
  70. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  71. EP260214a: VLT/FORS2 optical observations
  72. GRB 260225A: WINTER J-band upper limit
  73. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  74. GRB 260226A: COLIBRÍ optical upper limits
  75. GRB 260226A: LCOGT Optical Upper Limit
  76. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  77. GRB 260226A: Glowbug gamma-ray detection
  78. GRB 260226A: NuSTAR detection of bright prompt emission
  79. GRB 260226A : GROWTH-India Telescope optical observations
  80. GRB 260226A: LAST optical upper limit
  81. GRB 260226A: Fermi GBM observation
  82. GRB 260226A: Fermi-LAT refined analysis
  83. Fermi GRB 260226A: Global MASTER-Net observations report
  84. GRB 260226A: AstroSat CZTI detection of bright long burst
  85. EP260214a: VLA 6 GHz detection
  86. GRB 260226A: Fermi-LAT detection of a bright burst
  87. EP260224a: LCO optical upper limits
  88. GRB260225A: SVOM/ECLAIRs refined position
  89. GRB 260225A: EP-FXT follow-up observation
  90. GRB 260225A: SVOM/VT optical observation
  91. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  92. GRB 260223A: Fermi GBM Observation
  93. GRB 260225A: SVOM/VT optical upper limits
  94. EP260126a: VLA 6 GHz detection
  95. EP260223a: Liverpool Telescope upper limits
  96. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  97. EP 260225.148: COLIBRÍ Confirmation of flaring star
  98. EP260223a: Xinglong optical upper limit
  99. GRB 260223A: Glowbug gamma-ray detection
  100. EP260213a: Mephisto optical upper limits

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