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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"

2433 results found.

  1. GRB 260310A: Fermi GBM Observation
  2. GRB 260310A: potential optical counterpart
  3. Fermi GRB 260312B: Global MASTER-Net observations report
  4. Fermi GRB 260311B: Global MASTER-Net observations report
  5. GRB 260312B: BALROG localization (Fermi Trigger 795001611 / GRB 260312407)
  6. GRB 260312B: Fermi GBM Final Real-time Localization
  7. The EP-WXT trigger 01709258843 is not a real source
  8. GRB 260310B: GECAM-B observation of a burst
  9. GRB 260311B: Fermi GBM Final Real-time Localization
  10. GRB 260131A/B: radio detection with the VLA
  11. EP260302a: MeerKAT radio counterpart
  12. GRB260307A: GECAM-B observation of a burst
  13. GRB 260308A: SVOM/GRM observation of a short GRB
  14. EP260306a: Mondy optical upper limit
  15. GRB 260310A: AstroSat CZTI detection of a long burst
  16. GRB 260311A: Fermi GBM Final Real-time Localization
  17. Fermi GRB 260310B: Global MASTER-Net observations report
  18. GRB 260310B: Fermi GBM Final Real-time Localization
  19. Fermi GRB 260310A: Global MASTER-Net observations report
  20. GRB 260307B: SVOM/ECLAIRs refined analysis
  21. GRB 260208A: radio detection with the VLA
  22. GRB 260310A: Fermi GBM Final Real-time Localization
  23. GRB 260307A: Glowbug gamma-ray detection
  24. GRB 260308A: Fermi GBM Final Real-time Localization
  25. Fermi GBM Sub-Threshold Detection of GRB 260307B
  26. GRB 260307B: Mephisto optical upper limits
  27. GRB 260307B: possible NOT optical counterpart
  28. GRB 260307B: SVOM/VT upper limit with X band data analysis
  29. Fermi GRB 260307A: Global MASTER-Net observations report
  30. GRB260307B: GROWTH-India Telescope optical upper limit
  31. GRB 260307B: SVOM/VT optical candidate
  32. GRB 260307B: SVOM/C-GFT upper limit
  33. GRB 260307B: SVOM detection of a burst
  34. GRB 260307A: Fermi GBM Final Localization
  35. EP260306a: refined analysis of the EP-WXT and EP-FXT observations
  36. EP260302a: SVOM/VT optical observation
  37. EP260306a: Gemini-North redshift z = 4.773
  38. EP260306a: SVOM/VT optical observation
  39. EP260302a: Gemini-South redshift z = 1.535
  40. EP260306a: COLIBRÍ optical observations of the fading and red counterpart
  41. EP260306a: Einstein Probe detection of an X-ray transient
  42. EP260302a: Optical afterglow rebrightening
  43. GRB 260228A: further EP-FXT observations and X-ray afterglow confirmation
  44. GRB 260303A: 1.3m DFOT optical upper limit
  45. EP260214b: ATCA 6 GHz observations
  46. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  47. GRB 260303A: SVOM/ECLAIRs refined analysis
  48. Fermi GRB 260305A: Global MASTER-Net observations report
  49. GRB 260305A: Fermi GBM Final Real-time Localization
  50. GRB 260303B: AstroSat CZTI detection
  51. GRB 260304A: AstroSat CZTI detection of a long burst
  52. SVOM/sb26030408: SVOM detection of an X-ray transient likely associated with Beta Persei
  53. GRB 260303A: SVOM/VT optical observations
  54. GRB 260303A: J-band observations with WINTER
  55. GRB 260303B: NuSTAR detection of prompt emission
  56. EP260302a: Global MASTER-Net observations report
  57. Fermi GRB 260303B: Global MASTER-Net observations report
  58. IceCube-260217A: No Candidate Transients from the Zwicky Transient Facility
  59. GRB 260228A: SVOM/ECLAIRs refined analysis
  60. GRB 260225A: SVOM/ECLAIRs refined analysis
  61. GRB 260303B: BALROG localization (Fermi Trigger 794237065 / GRB 260303559)
  62. GRB 260303B: Fermi GBM Final Real-time Localization
  63. EP260302a: analysis of the follow-up EP-FXT observation
  64. EP260227a: Gemini-South optical observations
  65. EP260302a: LCO observations
  66. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  67. GRB 260303A: SVOM detection of a burst
  68. GRB 260228A: EP-FXT follow-up observation
  69. EP260302a: Einstein Probe detection of an X-ray transient
  70. GRB 260208A: TERI Gamma-ray detection
  71. GRB 260302A: Fermi GBM Final Real-time Localization
  72. EP260227a: Mondy optical observations
  73. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  74. EP260227a: Mephisto optical detection
  75. GRID detection of GRB 260225D
  76. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  77. EP260227a: further LCO observations
  78. EP260227a: SVOM/VT optical observation
  79. GRB 260228A: SVOM/VT optical upper limits
  80. GRB 260225D: SVOM/GRM observation
  81. EP260227A: 3.6m DOT optical afterglow detection
  82. GRB 260225B: SVOM/GRM observation
  83. GRB 260228A: SVOM detection of a burst
  84. EP260227a: FTW optical and NIR observations
  85. EP260227a: Liverpool Telescope optical observations
  86. EP260227a: Thai National Telescope observations
  87. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  88. EP260227a: Liverpool Telescope observations
  89. EP260227a: COLIBRÍ optical observations
  90. EP260227a: NOT optical observations
  91. GRID detection of GRB 260223A
  92. EP260227a: Global MASTER-Net observations report
  93. EP260227a: Einstein Probe detection of an X-ray transient and refined analysis
  94. EP/WXT trigger 01709258681 (EP260227a?): LCO candidate afterglow
  95. GRB 260226A: Insight-HXMT/HE detection of the very bright burst
  96. GRB 260223A: 7DT detection and Medium-band SED of Afterglow
  97. GRB 260225A: WINTER J-band upper limit
  98. GRB 260226A: CALET Gamma-Ray Burst Monitor detection
  99. GRB 260226A: COLIBRÍ optical upper limits
  100. EP-WXT trigger 01709258652: SVOM/C-GFT confirmation of a stellar flare

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