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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"

19316 results found.

  1. GRB 260225A: SVOM/ECLAIRs refined analysis
  2. GRB 260303B: BALROG localization (Fermi Trigger 794237065 / GRB 260303559)
  3. GRB 260303B: Fermi GBM Final Real-time Localization
  4. EP260302a: analysis of the follow-up EP-FXT observation
  5. EP260227a: Gemini-South optical observations
  6. EP260302a: LCO observations
  7. EP260302a: BOOTES-7 optical counterpart detection at early times
  8. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  9. GRB 260303A: SVOM detection of a burst
  10. GRB 260228A: EP-FXT follow-up observation
  11. EP260302a: Einstein Probe detection of an X-ray transient
  12. The EP-WXT trigger 01709258736: Las Cumbres discovery of the optical counterpart
  13. GRB 251130B: TERI Gamma-ray detection
  14. GRB 260208A: TERI Gamma-ray detection
  15. GRB 260302A: Fermi GBM Final Real-time Localization
  16. EP260227a: Mondy optical observations
  17. GRB 260228A: CAHA 2.2m telescope optical upper limit
  18. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  19. EP260227a: Mephisto optical detection
  20. GRID detection of GRB 260225D
  21. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  22. EP260227a: further LCO observations
  23. EP260227a: SVOM/VT optical observation
  24. GRB 260228A: SVOM/VT optical upper limits
  25. GRB 260225D: SVOM/GRM observation
  26. EP260227A: 3.6m DOT optical afterglow detection
  27. GRB 260225B: SVOM/GRM observation
  28. GRB 260228A: SVOM detection of a burst
  29. EP260227a: FTW optical and NIR observations
  30. EP260227a: Liverpool Telescope optical observations
  31. EP260227a: LCOGT Optical Observations
  32. EP260227a: Thai National Telescope observations
  33. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  34. EP260227a: Liverpool Telescope observations
  35. EP260227a: COLIBRÍ optical observations
  36. EP260227a: NOT optical observations
  37. GRID detection of GRB 260223A
  38. EP260227a: Global MASTER-Net observations report
  39. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  40. The EP-WXT trigger 01709258681 (EP260227a?): Las Cumbres follow-up observation of the optical counterpart
  41. EP/WXT trigger 01709258681 (EP260227a?): LCO candidate afterglow
  42. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  43. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  44. EP260214a: VLT/FORS2 optical observations
  45. GRB 260225A: WINTER J-band upper limit
  46. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  47. GRB 260226A: COLIBRÍ optical upper limits
  48. GRB 260226A: LCOGT Optical Upper Limit
  49. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  50. GRB 260225D: Glowbug gamma-ray detection of a likely short burst
  51. GRB 260226A: Glowbug gamma-ray detection
  52. GRB 260226A: NuSTAR detection of bright prompt emission
  53. GRB 260226A : GROWTH-India Telescope optical observations
  54. GRB 260226A: LAST optical upper limit
  55. GRB 260226A: Fermi GBM observation
  56. GRB 260226A: Fermi-LAT refined analysis
  57. The EP-WXT trigger 01709258652 is likely a flaring star
  58. LAT GRB260226.44: Global MASTER-Net observations report
  59. Fermi GRB 260226A: Global MASTER-Net observations report
  60. GRB 260226A: AstroSat CZTI detection of bright long burst
  61. EP260214a: VLA 6 GHz detection
  62. GRB 260226A: Fermi-LAT detection of a bright burst
  63. GRB 260226A???: BALROG localization (Fermi Trigger 793795080 / GRB 260226443)
  64. EP260224a: LCO optical upper limits
  65. GRB 260226A: Fermi GBM Final Real-time Localization
  66. GRB 260225A: EP-FXT follow-up observation
  67. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  68. GRB 260225C: Fermi GBM Final Real-time Localization
  69. GRB 260223A: Fermi GBM Observation
  70. GRB 260225A: SVOM/VT optical upper limits
  71. GRB 260225B: Fermi GBM Final Real-time Localization
  72. EP260126a: VLA 6 GHz detection
  73. EP260223a: Liverpool Telescope upper limits
  74. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  75. GRB 260225A: SVOM detection of a burst
  76. EP260224a: Einstein Probe detection of an X-ray transient
  77. EP 260225.148: COLIBRÍ Confirmation of flaring star
  78. EP260223a: Xinglong optical upper limit
  79. The EP-WXT trigger 01709258631 is likely a flaring star
  80. GRB 260223A: Glowbug gamma-ray detection
  81. EP260213a: Mephisto optical upper limits
  82. EP260223a: EP-FXT follow-up observation
  83. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  84. sb26021801: SVOM/C-GFT upper limit
  85. EP260223a: COLIBRÍ optical upper limits
  86. EP260223a: Einstein Probe detection of an X-ray transient
  87. GRB 260223A: SVOM/VT optical observation
  88. GRB 260223A: SVOM/GRM observation
  89. GRB 260223A: COLIBRÍ further optical observations and a brightening
  90. EP260221a: Optical upper limit with Kinder observations
  91. GRB 260223A: COLIBRÍ optical observations
  92. GRB 260223A: DDOTI Optical Candidate
  93. GRB 260223A: BALROG localization (Fermi Trigger 793512674 / GRB 260223174)
  94. Fermi GRB 260223A: Global MASTER-Net observations report
  95. GRB 260223A: Fermi GBM Final Real-time Localization
  96. EP260221a: Liverpool Telescope detection of COLIBRÍ counterpart candidate
  97. EP260221a: COLIBRÍ optical counterpart candidate
  98. EP260221a: Gemini South z-band upper limit
  99. GRB 260222A: Fermi GBM Final Real-time Localization
  100. EP260221a: Global MASTER-Net observations report

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