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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"

32720 results found.

  1. EP260302a: MeerKAT radio counterpart
  2. GRB260307A: GECAM-B observation of a burst
  3. GRB 260308A: SVOM/GRM observation of a short GRB
  4. EP260306a: Mondy optical upper limit
  5. GRB 260310A: AstroSat CZTI detection of a long burst
  6. Fermi GRB 260310B: Global MASTER-Net observations report
  7. Fermi GRB 260310A: Global MASTER-Net observations report
  8. GRB 260307B: SVOM/ECLAIRs refined analysis
  9. GRB 260208A: radio detection with the VLA
  10. GRB 260307A: Glowbug gamma-ray detection
  11. Fermi GBM Sub-Threshold Detection of GRB 260307B
  12. GRB 260307B: Mephisto optical upper limits
  13. GRB 260307B: possible NOT optical counterpart
  14. GRB 260307B: SVOM/VT upper limit with X band data analysis
  15. Fermi GRB 260307A: Global MASTER-Net observations report
  16. GRB260307B: GROWTH-India Telescope optical upper limit
  17. GRB 260307B: SVOM/VT optical candidate
  18. GRB 260307B: SVOM/C-GFT upper limit
  19. GRB 260211A: late-time NOT i-band observations consistent with archival flux
  20. EP260306a: refined analysis of the EP-WXT and EP-FXT observations
  21. GRB 260207A: TESS Detection and Possible VLA Counterpart
  22. EP260302a: SVOM/VT optical observation
  23. EP260306a: Gemini-North redshift z = 4.773
  24. EP260306a: SVOM/VT optical observation
  25. EP260302a: Gemini-South redshift z = 1.535
  26. EP260306a: COLIBRÍ optical observations of the fading and red counterpart
  27. EP260306a: Einstein Probe detection of an X-ray transient
  28. EP260302a: Optical afterglow rebrightening
  29. GRB 260228A: further EP-FXT observations and X-ray afterglow confirmation
  30. GRB 260303A: 1.3m DFOT optical upper limit (duplicate submission)
  31. GRB 260303A: 1.3m DFOT optical upper limit
  32. EP260214b: ATCA 6 GHz observations
  33. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  34. GRB 260303A: SVOM/ECLAIRs refined analysis
  35. Fermi GRB 260305A: Global MASTER-Net observations report
  36. GRB 260303B: AstroSat CZTI detection
  37. GRB 260303A: SVOM/VT optical observations
  38. GRB 260303A: J-band observations with WINTER
  39. GRB 260303B: NuSTAR detection of prompt emission
  40. EP260302a: Global MASTER-Net observations report
  41. Fermi GRB 260303B: Global MASTER-Net observations report
  42. IceCube-260217A: No Candidate Transients from the Zwicky Transient Facility
  43. GRB 260228A: SVOM/ECLAIRs refined analysis
  44. GRB 260225A: SVOM/ECLAIRs refined analysis
  45. EP260302a: analysis of the follow-up EP-FXT observation
  46. EP260227a: Gemini-South optical observations
  47. EP260302a: LCO observations
  48. EP260302a: BOOTES-7 optical counterpart detection at early times
  49. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  50. GRB 260228A: EP-FXT follow-up observation
  51. GRB 251130B: TERI Gamma-ray detection
  52. GRB 260208A: TERI Gamma-ray detection
  53. EP260227a: Mondy optical observations
  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. EP260227a: FTW optical and NIR observations
  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: Global MASTER-Net observations report
  76. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  77. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  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 260226A: Glowbug gamma-ray detection
  88. GRB 260226A: NuSTAR detection of bright prompt emission
  89. GRB 260226A : GROWTH-India Telescope optical observations
  90. GRB 260226A: LAST optical upper limit
  91. GRB 260226A: Fermi GBM observation
  92. GRB 260226A: Fermi-LAT refined analysis
  93. Fermi GRB 260226A: Global MASTER-Net observations report
  94. GRB 260226A: AstroSat CZTI detection of bright long burst
  95. EP260214a: VLA 6 GHz detection
  96. GRB 260226A: Fermi-LAT detection of a bright burst
  97. EP260224a: LCO optical upper limits
  98. GRB260225A: SVOM/ECLAIRs refined position
  99. GRB 260225A: EP-FXT follow-up observation
  100. GRB 260225A: SVOM/VT optical observation

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