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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"

42911 results found.

  1. Fermi GRB 260311B: Global MASTER-Net observations report
  2. Swift BAT trigger 1500148: A solar flare
  3. GRB 260312B: BALROG localization (Fermi Trigger 795001611 / GRB 260312407)
  4. GRB 260312B: Fermi GBM Final Real-time Localization
  5. GRB 260310B: GECAM-B observation of a burst
  6. Retraction of GCN 43965: GRB is actually solar flare
  7. GRB 260312A: Swift detection of a burst
  8. GRB 260311B: Fermi GBM Final Real-time Localization
  9. GRB 260131A/B: radio detection with the VLA
  10. EP260302a: MeerKAT radio counterpart
  11. GRB260307A: GECAM-B observation of a burst
  12. GRB 260308A: SVOM/GRM observation of a short GRB
  13. EP260306a: Mondy optical upper limit
  14. GRB 260310A: AstroSat CZTI detection of a long burst
  15. GRB 260311A: Fermi GBM Final Real-time Localization
  16. Fermi GRB 260310B: Global MASTER-Net observations report
  17. GRB 260310B: Fermi GBM Final Real-time Localization
  18. Fermi GRB 260310A: Global MASTER-Net observations report
  19. GRB 260307B: SVOM/ECLAIRs refined analysis
  20. GRB 260208A: radio detection with the VLA
  21. GRB 260310A: Fermi GBM Final Real-time Localization
  22. GRB 260307A: Glowbug gamma-ray detection
  23. GRB 260308A: Fermi GBM Final Real-time Localization
  24. Fermi GBM Sub-Threshold Detection of GRB 260307B
  25. GRB 260307B: Mephisto optical upper limits
  26. GRB 260307B: possible NOT optical counterpart
  27. GRB 260307B: SVOM/VT upper limit with X band data analysis
  28. Fermi GRB 260307A: Global MASTER-Net observations report
  29. GRB260307B: GROWTH-India Telescope optical upper limit
  30. GRB 260307B: SVOM/VT optical candidate
  31. GRB 260307B: SVOM/C-GFT upper limit
  32. GRB 260307B: SVOM detection of a burst
  33. GRB 260307A: Fermi GBM Final Localization
  34. GRB 260211A: late-time NOT i-band observations consistent with archival flux
  35. EP260306a: refined analysis of the EP-WXT and EP-FXT observations
  36. GRB 260207A: TESS Detection and Possible VLA Counterpart
  37. EP260302a: SVOM/VT optical observation
  38. EP260306a: Gemini-North redshift z = 4.773
  39. EP260306a: SVOM/VT optical observation
  40. EP260302a: Gemini-South redshift z = 1.535
  41. EP260306a: COLIBRÍ optical observations of the fading and red counterpart
  42. EP260306a: Einstein Probe detection of an X-ray transient
  43. The EP-WXT trigger 01709258759: Las Cumbres discovery of the optical counterpart
  44. EP260302a: Optical afterglow rebrightening
  45. GRB 260228A: further EP-FXT observations and X-ray afterglow confirmation
  46. GRB 260303A: 1.3m DFOT optical upper limit
  47. EP260214b: ATCA 6 GHz observations
  48. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  49. GRB 260303A: SVOM/ECLAIRs refined analysis
  50. Fermi GRB 260305A: Global MASTER-Net observations report
  51. GRB 260305A: Fermi GBM Final Real-time Localization
  52. GRB 260303B: AstroSat CZTI detection
  53. GRB 260304A: AstroSat CZTI detection of a long burst
  54. SVOM/sb26030408: SVOM detection of an X-ray transient likely associated with Beta Persei
  55. GRB 260303A: SVOM/VT optical observations
  56. GRB 260303A: J-band observations with WINTER
  57. GRB 260303B: NuSTAR detection of prompt emission
  58. EP260302a: Global MASTER-Net observations report
  59. Fermi GRB 260303B: Global MASTER-Net observations report
  60. IceCube-260217A: No Candidate Transients from the Zwicky Transient Facility
  61. GRB 260228A: SVOM/ECLAIRs refined analysis
  62. GRB 260225A: SVOM/ECLAIRs refined analysis
  63. GRB 260303B: BALROG localization (Fermi Trigger 794237065 / GRB 260303559)
  64. GRB 260303B: Fermi GBM Final Real-time Localization
  65. EP260302a: analysis of the follow-up EP-FXT observation
  66. EP260227a: Gemini-South optical observations
  67. EP260302a: LCO observations
  68. EP260302a: BOOTES-7 optical counterpart detection at early times
  69. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  70. GRB 260303A: SVOM detection of a burst
  71. GRB 260228A: EP-FXT follow-up observation
  72. EP260302a: Einstein Probe detection of an X-ray transient
  73. The EP-WXT trigger 01709258736: Las Cumbres discovery of the optical counterpart
  74. GRB 251130B: TERI Gamma-ray detection
  75. GRB 260208A: TERI Gamma-ray detection
  76. GRB 260302A: Fermi GBM Final Real-time Localization
  77. EP260227a: Mondy optical observations
  78. GRB 260228A: CAHA 2.2m telescope optical upper limit
  79. GRB 260228A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  80. EP260227a: Mephisto optical detection
  81. GRID detection of GRB 260225D
  82. EP-WXT trigger 01709258652: 50cm Telescope multi-band observations
  83. EP260227a: further LCO observations
  84. EP260227a: SVOM/VT optical observation
  85. GRB 260228A: SVOM/VT optical upper limits
  86. GRB 260225D: SVOM/GRM observation
  87. EP260227A: 3.6m DOT optical afterglow detection
  88. GRB 260225B: SVOM/GRM observation
  89. GRB 260228A: SVOM detection of a burst
  90. EP260227a: FTW optical and NIR observations
  91. EP260227a: Liverpool Telescope optical observations
  92. EP260227a: LCOGT Optical Observations
  93. GRB 260226A: Asiago r-band upper limit
  94. EP260227a: Thai National Telescope observations
  95. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  96. EP260227a: Liverpool Telescope observations
  97. EP260227a: COLIBRÍ optical observations
  98. EP260227a: NOT optical observations
  99. GRB 260225A: SVOM/VT optical continued observations and upper limit
  100. GRID detection of GRB 260223A

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