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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"

2408 results found.

  1. GRB 260307B: Mephisto optical upper limits
  2. GRB 260307B: possible NOT optical counterpart
  3. GRB 260307B: SVOM/VT upper limit with X band data analysis
  4. Fermi GRB 260307A: Global MASTER-Net observations report
  5. GRB260307B: GROWTH-India Telescope optical upper limit
  6. GRB 260307B: SVOM/VT optical candidate
  7. GRB 260307B: SVOM/C-GFT upper limit
  8. GRB 260307B: SVOM detection of a burst
  9. GRB 260307A: Fermi GBM Final Localization
  10. EP260306a: refined analysis of the EP-WXT and EP-FXT observations
  11. EP260302a: SVOM/VT optical observation
  12. EP260306a: Gemini-North redshift z = 4.773
  13. EP260306a: SVOM/VT optical observation
  14. EP260302a: Gemini-South redshift z = 1.535
  15. EP260306a: COLIBRÍ optical observations of the fading and red counterpart
  16. EP260306a: Einstein Probe detection of an X-ray transient
  17. EP260302a: Optical afterglow rebrightening
  18. GRB 260228A: further EP-FXT observations and X-ray afterglow confirmation
  19. GRB 260303A: 1.3m DFOT optical upper limit
  20. EP260214b: ATCA 6 GHz observations
  21. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  22. GRB 260303A: SVOM/ECLAIRs refined analysis
  23. Fermi GRB 260305A: Global MASTER-Net observations report
  24. GRB 260305A: Fermi GBM Final Real-time Localization
  25. GRB 260303B: AstroSat CZTI detection
  26. GRB 260304A: AstroSat CZTI detection of a long burst
  27. SVOM/sb26030408: SVOM detection of an X-ray transient likely associated with Beta Persei
  28. GRB 260303A: SVOM/VT optical observations
  29. GRB 260303A: J-band observations with WINTER
  30. GRB 260303B: NuSTAR detection of prompt emission
  31. EP260302a: Global MASTER-Net observations report
  32. Fermi GRB 260303B: Global MASTER-Net observations report
  33. IceCube-260217A: No Candidate Transients from the Zwicky Transient Facility
  34. GRB 260228A: SVOM/ECLAIRs refined analysis
  35. GRB 260225A: SVOM/ECLAIRs refined analysis
  36. GRB 260303B: BALROG localization (Fermi Trigger 794237065 / GRB 260303559)
  37. GRB 260303B: Fermi GBM Final Real-time Localization
  38. EP260302a: analysis of the follow-up EP-FXT observation
  39. EP260227a: Gemini-South optical observations
  40. EP260302a: LCO observations
  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. GRB 260208A: TERI Gamma-ray detection
  46. GRB 260302A: Fermi GBM Final Real-time Localization
  47. EP260227a: Mondy optical observations
  48. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  49. EP260227a: Mephisto optical detection
  50. GRID detection of GRB 260225D
  51. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  52. EP260227a: further LCO 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. GRB 260228A: SVOM detection of a burst
  59. EP260227a: FTW optical and NIR observations
  60. EP260227a: Liverpool Telescope optical observations
  61. EP260227a: Thai National Telescope observations
  62. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  63. EP260227a: Liverpool Telescope observations
  64. EP260227a: COLIBRÍ optical observations
  65. EP260227a: NOT optical observations
  66. GRID detection of GRB 260223A
  67. EP260227a: Global MASTER-Net observations report
  68. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  69. EP/WXT trigger 01709258681 (EP260227a?): LCO candidate afterglow
  70. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  71. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  72. GRB 260225A: WINTER J-band upper limit
  73. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  74. GRB 260226A: COLIBRÍ optical upper limits
  75. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare
  76. GRB 260225D: Glowbug gamma-ray detection of a likely short burst
  77. GRB 260226A: Glowbug gamma-ray detection
  78. GRB 260226A: NuSTAR detection of bright prompt emission
  79. GRB 260226A : GROWTH-India Telescope optical observations
  80. GRB 260226A: LAST optical upper limit
  81. GRB 260226A: Fermi GBM observation
  82. GRB 260226A: Fermi-LAT refined analysis
  83. The EP-WXT trigger 01709258652 is likely a flaring star
  84. LAT GRB260226.44: Global MASTER-Net observations report
  85. Fermi GRB 260226A: Global MASTER-Net observations report
  86. GRB 260226A: AstroSat CZTI detection of bright long burst
  87. EP260214a: VLA 6 GHz detection
  88. GRB 260226A: Fermi-LAT detection of a bright burst
  89. GRB 260226A???: BALROG localization (Fermi Trigger 793795080 / GRB 260226443)
  90. EP260224a: LCO optical upper limits
  91. GRB 260226A: Fermi GBM Final Real-time Localization
  92. GRB 260225A: EP-FXT follow-up observation
  93. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  94. GRB 260225C: Fermi GBM Final Real-time Localization
  95. GRB 260223A: Fermi GBM Observation
  96. GRB 260225A: SVOM/VT optical upper limits
  97. GRB 260225B: Fermi GBM Final Real-time Localization
  98. EP260126a: VLA 6 GHz detection
  99. EP260223a: Liverpool Telescope upper limits
  100. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits

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