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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"

45888 results found.

  1. GRB 260228A: SVOM/ECLAIRs refined analysis
  2. GRB 260225A: SVOM/ECLAIRs refined analysis
  3. GRB 260303B: BALROG localization (Fermi Trigger 794237065 / GRB 260303559)
  4. GRB 260303B: Fermi GBM Final Real-time Localization
  5. EP260302a: analysis of the follow-up EP-FXT observation
  6. EP260227a: Gemini-South optical observations
  7. EP260302a: LCO observations
  8. EP260302a: BOOTES-7 optical counterpart detection at early times
  9. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  10. GRB 260303A: SVOM detection of a burst
  11. GRB 260228A: EP-FXT follow-up observation
  12. EP260302a: Einstein Probe detection of an X-ray transient
  13. The EP-WXT trigger 01709258736: Las Cumbres discovery of the optical counterpart
  14. GRB 251130B: TERI Gamma-ray detection
  15. GRB 260208A: TERI Gamma-ray detection
  16. GRB 260302A: Fermi GBM Final Real-time Localization
  17. EP260227a: Mondy optical observations
  18. GRB 260228A: CAHA 2.2m telescope optical upper limit
  19. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  20. EP260227a: Mephisto optical detection
  21. GRID detection of GRB 260225D
  22. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  23. EP260227a: further LCO observations
  24. EP260227a: SVOM/VT optical observation
  25. GRB 260228A: SVOM/VT optical upper limits
  26. GRB 260225D: SVOM/GRM observation
  27. EP260227A: 3.6m DOT optical afterglow detection
  28. GRB 260225B: SVOM/GRM observation
  29. GRB 260228A: SVOM detection of a burst
  30. EP260227a: FTW optical and NIR observations
  31. EP260227a: Liverpool Telescope optical observations
  32. EP260227a: LCOGT Optical Observations
  33. GRB 260226A: Asiago r-band upper limit
  34. EP260227a: Thai National Telescope observations
  35. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  36. EP260227a: Liverpool Telescope observations
  37. EP260227a: COLIBRÍ optical observations
  38. EP260227a: NOT optical observations
  39. GRB 260225A: SVOM/VT optical continued observations and upper limit
  40. GRID detection of GRB 260223A
  41. EP260227a: Global MASTER-Net observations report
  42. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  43. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  44. EP/WXT trigger 01709258681 (EP260227a?): LCO candidate afterglow
  45. IceCube cascade alert 142200_1517143 retraction
  46. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  47. Konus-Wind detection of GRB 260226A
  48. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  49. EP260214a: VLT/FORS2 optical observations
  50. GRB 260225A: WINTER J-band upper limit
  51. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  52. GRB 260226A: COLIBRÍ optical upper limits
  53. GRB 260226A: LCOGT Optical Upper Limit
  54. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  55. GRB 260225D: Glowbug gamma-ray detection of a likely short burst
  56. GRB 260226A: Glowbug gamma-ray detection
  57. GRB 260226A: NuSTAR detection of bright prompt emission
  58. GRB 260226A : GROWTH-India Telescope optical observations
  59. GRB 260226A: LAST optical upper limit
  60. GRB 260226A: Fermi GBM observation
  61. GRB 260226A: Fermi-LAT refined analysis
  62. The EP-WXT trigger 01709258652 is likely a flaring star
  63. LAT GRB260226.44: Global MASTER-Net observations report
  64. Fermi GRB 260226A: Global MASTER-Net observations report
  65. GRB 260226A: AstroSat CZTI detection of bright long burst
  66. EP260214a: VLA 6 GHz detection
  67. GRB 260226A: Fermi-LAT detection of a bright burst
  68. GRB 260226A???: BALROG localization (Fermi Trigger 793795080 / GRB 260226443)
  69. EP260224a: LCO optical upper limits
  70. GRB260225A: SVOM/ECLAIRs refined position
  71. GRB 260226A: Fermi GBM Final Real-time Localization
  72. GRB 260225A: EP-FXT follow-up observation
  73. GRB 260225A: SVOM/VT optical observation
  74. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  75. GRB 260225C: Fermi GBM Final Real-time Localization
  76. GRB 260223A: Fermi GBM Observation
  77. GRB 260225A: SVOM/VT optical upper limits
  78. GRB 260225B: Fermi GBM Final Real-time Localization
  79. EP260126a: VLA 6 GHz detection
  80. EP260223a: Liverpool Telescope upper limits
  81. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  82. GRB 260225A: SVOM detection of a burst
  83. EP260224a: Einstein Probe detection of an X-ray transient
  84. EP 260225.148: COLIBRÍ Confirmation of flaring star
  85. EP260223a: Xinglong optical upper limit
  86. The EP-WXT trigger 01709258631 is likely a flaring star
  87. GRB 260223A: Glowbug gamma-ray detection
  88. EP260213a: Mephisto optical upper limits
  89. EP260223a: EP-FXT follow-up observation
  90. sb26021801: SVOM/VT optical upper limits
  91. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  92. sb26021801: SVOM/C-GFT upper limit
  93. EP260223a: COLIBRÍ optical upper limits
  94. EP260223a: Einstein Probe detection of an X-ray transient
  95. GRB 260223A: SVOM/VT optical observation
  96. GRB 260223A: SVOM/GRM observation
  97. GRB 260223A: COLIBRÍ further optical observations and a brightening
  98. EP260221a: Optical upper limit with Kinder observations
  99. GRB 260223A: COLIBRÍ optical observations
  100. GRB 260223A: DDOTI Optical Candidate

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