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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"

28125 results found.

  1. GRB 260312B: BALROG localization (Fermi Trigger 795001611 / GRB 260312407)
  2. GRB 260131A/B: radio detection with the VLA
  3. EP260302a: MeerKAT radio counterpart
  4. GRB 260308A: SVOM/GRM observation of a short GRB
  5. EP260306a: Mondy optical upper limit
  6. Fermi GRB 260310B: Global MASTER-Net observations report
  7. Fermi GRB 260310A: Global MASTER-Net observations report
  8. GRB 260208A: radio detection with the VLA
  9. GRB 260307A: Glowbug gamma-ray detection
  10. Fermi GBM Sub-Threshold Detection of GRB 260307B
  11. GRB 260307B: Mephisto optical upper limits
  12. GRB 260307B: possible NOT optical counterpart
  13. GRB 260307B: SVOM/VT upper limit with X band data analysis
  14. Fermi GRB 260307A: Global MASTER-Net observations report
  15. GRB260307B: GROWTH-India Telescope optical upper limit
  16. GRB 260307B: SVOM/VT optical candidate
  17. GRB 260307B: SVOM/C-GFT upper limit
  18. GRB 260307B: SVOM detection of a burst
  19. EP260306a: refined analysis of the EP-WXT and EP-FXT observations
  20. GRB 260207A: TESS Detection and Possible VLA Counterpart
  21. EP260302a: SVOM/VT optical observation
  22. EP260306a: Gemini-North redshift z = 4.773
  23. EP260306a: SVOM/VT optical observation
  24. EP260302a: Gemini-South redshift z = 1.535
  25. EP260306a: COLIBRÍ optical observations of the fading and red counterpart
  26. EP260306a: Einstein Probe detection of an X-ray transient
  27. EP260302a: Optical afterglow rebrightening
  28. GRB 260228A: further EP-FXT observations and X-ray afterglow confirmation
  29. GRB 260303A: 1.3m DFOT optical upper limit
  30. Fermi GRB 260305A: Global MASTER-Net observations report
  31. GRB 260303B: AstroSat CZTI detection
  32. GRB 260303A: SVOM/VT optical observations
  33. GRB 260303A: J-band observations with WINTER
  34. GRB 260303B: NuSTAR detection of prompt emission
  35. EP260302a: Global MASTER-Net observations report
  36. Fermi GRB 260303B: Global MASTER-Net observations report
  37. GRB 260303B: BALROG localization (Fermi Trigger 794237065 / GRB 260303559)
  38. EP260302a: analysis of the follow-up EP-FXT observation
  39. EP260302a: LCO observations
  40. EP260302a: BOOTES-7 optical counterpart detection at early times
  41. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  42. GRB 260303A: SVOM detection of a burst
  43. GRB 260228A: EP-FXT follow-up observation
  44. EP260302a: Einstein Probe detection of an X-ray transient
  45. The EP-WXT trigger 01709258736: Las Cumbres discovery of the optical counterpart
  46. GRB 251130B: TERI Gamma-ray detection
  47. GRB 260208A: TERI Gamma-ray detection
  48. EP260227a: Mondy optical observations
  49. GRB 260228A: CAHA 2.2m telescope optical upper limit
  50. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  51. EP260227a: Mephisto optical detection
  52. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  53. EP260227a: SVOM/VT optical observation
  54. GRB 260228A: SVOM/VT optical upper limits
  55. GRB 260225D: SVOM/GRM observation
  56. EP260227A: 3.6m DOT optical afterglow detection
  57. GRB 260225B: SVOM/GRM observation
  58. EP260227a: Liverpool Telescope optical observations
  59. EP260227a: LCOGT Optical Observations
  60. GRB 260226A: Asiago r-band upper limit
  61. EP260227a: Liverpool Telescope observations
  62. EP260227a: COLIBRÍ optical observations
  63. EP260227a: NOT optical observations
  64. EP260227a: Global MASTER-Net observations report
  65. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  66. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  67. EP/WXT trigger 01709258681 (EP260227a?): LCO candidate afterglow
  68. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  69. EP260214a: VLT/FORS2 optical observations
  70. GRB 260225A: WINTER J-band upper limit
  71. GRB 260226A: COLIBRÍ optical upper limits
  72. GRB 260226A: LCOGT Optical Upper Limit
  73. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  74. GRB 260225D: Glowbug gamma-ray detection of a likely short burst
  75. GRB 260226A: Glowbug gamma-ray detection
  76. GRB 260226A: NuSTAR detection of bright prompt emission
  77. GRB 260226A : GROWTH-India Telescope optical observations
  78. GRB 260226A: LAST optical upper limit
  79. GRB 260226A: Fermi GBM observation
  80. LAT GRB260226.44: Global MASTER-Net observations report
  81. Fermi GRB 260226A: Global MASTER-Net observations report
  82. GRB 260226A: AstroSat CZTI detection of bright long burst
  83. GRB 260226A???: BALROG localization (Fermi Trigger 793795080 / GRB 260226443)
  84. EP260224a: LCO optical upper limits
  85. GRB 260225A: EP-FXT follow-up observation
  86. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  87. GRB 260223A: Fermi GBM Observation
  88. GRB 260225A: SVOM/VT optical upper limits
  89. EP260223a: Liverpool Telescope upper limits
  90. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  91. EP260224a: Einstein Probe detection of an X-ray transient
  92. EP 260225.148: COLIBRÍ Confirmation of flaring star
  93. EP260223a: Xinglong optical upper limit
  94. GRB 260223A: Glowbug gamma-ray detection
  95. EP260213a: Mephisto optical upper limits
  96. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  97. sb26021801: SVOM/C-GFT upper limit
  98. EP260223a: COLIBRÍ optical upper limits
  99. EP260223a: Einstein Probe detection of an X-ray transient
  100. GRB 260223A: SVOM/GRM observation

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