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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"

45508 results found.

  1. GRB 260307B: SVOM detection of a burst
  2. GRB 260307A: Fermi GBM Final Localization
  3. GRB 260211A: late-time NOT i-band observations consistent with archival flux
  4. EP260306a: refined analysis of the EP-WXT and EP-FXT observations
  5. GRB 260207A: TESS Detection and Possible VLA Counterpart
  6. EP260302a: SVOM/VT optical observation
  7. EP260306a: Gemini-North redshift z = 4.773
  8. EP260306a: SVOM/VT optical observation
  9. EP260302a: Gemini-South redshift z = 1.535
  10. EP260306a: COLIBRÍ optical observations of the fading and red counterpart
  11. EP260306a: Einstein Probe detection of an X-ray transient
  12. The EP-WXT trigger 01709258759: Las Cumbres discovery of the optical counterpart
  13. EP260302a: Optical afterglow rebrightening
  14. GRB 260228A: further EP-FXT observations and X-ray afterglow confirmation
  15. GRB 260303A: 1.3m DFOT optical upper limit (duplicate submission)
  16. GRB 260303A: 1.3m DFOT optical upper limit
  17. EP260214b: ATCA 6 GHz observations
  18. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  19. GRB 260303A: SVOM/ECLAIRs refined analysis
  20. Fermi GRB 260305A: Global MASTER-Net observations report
  21. GRB 260305A: Fermi GBM Final Real-time Localization
  22. GRB 260303B: AstroSat CZTI detection
  23. GRB 260304A: AstroSat CZTI detection of a long burst
  24. SVOM/sb26030408: SVOM detection of an X-ray transient likely associated with Beta Persei
  25. GRB 260303A: SVOM/VT optical observations
  26. GRB 260303A: J-band observations with WINTER
  27. GRB 260303B: NuSTAR detection of prompt emission
  28. EP260302a: Global MASTER-Net observations report
  29. Fermi GRB 260303B: Global MASTER-Net observations report
  30. IceCube-260217A: No Candidate Transients from the Zwicky Transient Facility
  31. GRB 260228A: SVOM/ECLAIRs refined analysis
  32. GRB 260225A: SVOM/ECLAIRs refined analysis
  33. GRB 260303B: BALROG localization (Fermi Trigger 794237065 / GRB 260303559)
  34. GRB 260303B: Fermi GBM Final Real-time Localization
  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 260303A: SVOM detection of a burst
  41. GRB 260228A: EP-FXT follow-up observation
  42. EP260302a: Einstein Probe detection of an X-ray transient
  43. The EP-WXT trigger 01709258736: Las Cumbres discovery of the optical counterpart
  44. GRB 251130B: TERI Gamma-ray detection
  45. GRB 260208A: TERI Gamma-ray detection
  46. GRB 260302A: Fermi GBM Final Real-time Localization
  47. EP260227a: Mondy optical observations
  48. GRB 260228A: CAHA 2.2m telescope optical upper limit
  49. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  50. EP260227a: Mephisto optical detection
  51. GRID detection of GRB 260225D
  52. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  53. EP260227a: further LCO observations
  54. EP260227a: SVOM/VT optical observation
  55. GRB 260228A: SVOM/VT optical upper limits
  56. GRB 260225D: SVOM/GRM observation
  57. EP260227A: 3.6m DOT optical afterglow detection
  58. GRB 260225B: SVOM/GRM observation
  59. GRB 260228A: SVOM detection of a burst
  60. EP260227a: FTW optical and NIR observations
  61. EP260227a: Liverpool Telescope optical observations
  62. EP260227a: LCOGT Optical Observations
  63. GRB 260226A: Asiago r-band upper limit
  64. EP260227a: Thai National Telescope observations
  65. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  66. EP260227a: Liverpool Telescope observations
  67. EP260227a: COLIBRÍ optical observations
  68. EP260227a: NOT optical observations
  69. GRB 260225A: SVOM/VT optical continued observations and upper limit
  70. GRID detection of GRB 260223A
  71. EP260227a: Global MASTER-Net observations report
  72. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  73. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  74. EP/WXT trigger 01709258681 (EP260227a?): LCO candidate afterglow
  75. IceCube cascade alert 142200_1517143 retraction
  76. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  77. Konus-Wind detection of GRB 260226A
  78. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  79. EP260214a: VLT/FORS2 optical observations
  80. GRB 260225A: WINTER J-band upper limit
  81. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  82. GRB 260226A: COLIBRÍ optical upper limits
  83. GRB 260226A: LCOGT Optical Upper Limit
  84. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  85. GRB 260225D: Glowbug gamma-ray detection of a likely short burst
  86. GRB 260226A: Glowbug gamma-ray detection
  87. GRB 260226A: NuSTAR detection of bright prompt emission
  88. GRB 260226A : GROWTH-India Telescope optical observations
  89. GRB 260226A: LAST optical upper limit
  90. GRB 260226A: Fermi GBM observation
  91. GRB 260226A: Fermi-LAT refined analysis
  92. The EP-WXT trigger 01709258652 is likely a flaring star
  93. LAT GRB260226.44: Global MASTER-Net observations report
  94. Fermi GRB 260226A: Global MASTER-Net observations report
  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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