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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"

2424 results found.

  1. GRB 260212A: GECAM-B observation
  2. EP260213a: Optical upper limits with Kinder observations
  3. EP260213a: SVOM/VT optical upper limit
  4. EP260213a: Mondy R-band optical upper limit
  5. EP260213a: NUTTelA-TAO Early Optical Limits
  6. EP260213a: SVOM/C-GFT upper limit
  7. EP260213a: refined analysis of the EP-FXT observation
  8. EP260213a: Einstein Probe detection of a fast X-ray transient
  9. EP/WXT 01709258378: NOT optical upper limits
  10. GRB 260212A: SVOM/GRM observation of a long burst
  11. GRB 260213B: Fermi GBM Final Localization
  12. GRB 260213B: BALROG localization (Fermi Trigger 792697214 / GRB 260213736)
  13. GRB 260211A - SVOM/ECLAIRs refined analysis
  14. GRB 260204A: SVOM/ECLAIRs refined analysis
  15. GRB 260213A: Fermi GBM Final Localization
  16. GRB 260211A: EP-FXT follow-up observation
  17. GRB 260211A: SVOM/VT optical observation
  18. GRB 260212A: Glowbug gamma-ray detection
  19. GRB 260211A: GOTO optical upper limit
  20. Fermi GRB 260212A: Global MASTER-Net observations report
  21. GRB 260212A: Fermi GBM Final Real-time Localization
  22. GRB 260211A: LAST optical upper limit
  23. GRB 260210A: SVOM/GRM observation
  24. Fermi GBM Sub-Threshold Detection of GRB 260211A
  25. GRB 260128B: SVOM/ECLAIRs refined analysis
  26. GRID detection of GRB 260207B
  27. GRB 260211A: LCO optical upper limits
  28. GRB260131A/B: 3.6m DOT Optical Observations
  29. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  30. Fermi trigger No 792537871: Global MASTER-Net observations report
  31. GRB 260211A: SVOM detection of a burst
  32. EP260209a: COLIBRÍ optical upper limit
  33. Fermi GRB 260210C: Global MASTER-Net observations report
  34. EP260209a: LCO optical upper limits
  35. EP260210a: Global MASTER-Net observations report
  36. EP260210a: refined analysis of the EP-FXT observation
  37. EP260209a: Global MASTER-Net observations report
  38. GRB 260208A: LCO detection of the optical counterpart
  39. EP260209a: Einstein Probe detection of a fast X-ray transient
  40. EP260210a: Optical upper limits with Kinder observations
  41. GRB 260210C: Fermi GBM Final Real-time Localization
  42. GRB 260210A: Glowbug gamma-ray detection
  43. GRB 260210B: Fermi GBM Final Real-time Localization
  44. EP260210a: SVOM/VT optical upper limit
  45. GRB 260210A: AstroSat CZTI detection
  46. GRB 260208C: AstroSat CZTI detection
  47. EP260210a: COLIBRÍ optical upper limit
  48. EP260210a: SVOM/C-GFT upper limit
  49. GRB 260208B: refined analysis of the EP-FXT observation
  50. EP260210a: Einstein Probe detection of an X-ray transient
  51. GRB 260207B: AstroSat CZTI detection
  52. GRB 260208C: SVOM/GRM observation
  53. GRB 260208B: AstroSat CZTI detection of a bright long burst
  54. GRB260208A: Liverpool Telescope optical follow-up observations
  55. GRB 260208A: Glowbug gamma-ray detection
  56. GRB 260208A: NuSTAR detection of prompt emission
  57. GRB 260208A: Fermi GBM Observation
  58. Fermi GRB 260209A: Global MASTER-Net observations report
  59. GRB 260131A/B: continued Mondy optical observations
  60. GRB 260208B: COLIBRÍ optical observations
  61. GRB 260208A: Mondy optical observations
  62. GRB 260208A: 1.3m DFOT optical detection
  63. GRB 260208A: COLIBRÍ optical observations
  64. GRB 260208B: EP-FXT observation
  65. GRB 260208A: NOT spectroscopic redshift z = 2.36
  66. GRB 260208A: Liverpool Telescope optical detection
  67. Fermi GRB 260208C: Global MASTER-Net observations report
  68. GRB 260208B: SVOM/VT optical candidate
  69. GRB 260208A: GECAM-B observation of a bright burst
  70. GRB 260208A: Zwicky Transient Facility Follow-Up of a Fermi GRB (Trigger 792220053)
  71. GRB 260209A: Fermi GBM Final Real-time Localization
  72. GRB 260208A: SVOM/VT optical observation
  73. Fermi GRB 260208D: Global MASTER-Net observations report
  74. GRB 260208D: Fermi GBM Final Real-time Localization
  75. GRB 260208B: SVOM/GRM observation of a bright burst
  76. GRB 260208B: Fermi GBM Detection
  77. LAT GRB 260208B: Global MASTER-Net observations report
  78. GRB 260208B: Fermi-LAT detection
  79. GRB 260208C: Fermi GBM Final Real-time Localization
  80. GRB 260208A: Fermi-LAT detection
  81. GRB 260207B: GECAM-B observation
  82. GRB 260208A: Fermi GBM Classification Correction
  83. GRB 260208A: GOTO detection of a potential optical counterpart (GOTO26aob)
  84. GRB 260208B: BALROG localization (Fermi Trigger 792237169 / GRB 260208412)
  85. GRB 260208B: Fermi GBM Final Real-time Localization
  86. Fermi GRB 260208A: Global MASTER-Net observations report
  87. Fermi Gamma-ray Burst Monitor trigger 792220053/260208214 is not a GRB
  88. GRB 260208A: Fermi GBM Final Real-time Localization
  89. GRB 260207B: Fermi GBM Detection of a Short Burst with Extended Emission
  90. GRB 260207A : MASTER optical counterpart discovery
  91. GRB 260131A/B: Mondy and Terskol optical observations
  92. Fermi GRB 260207B: Global MASTER-Net observations report
  93. GRB 260207B: Fermi GBM Final Real-time Localization
  94. GRB 260207A: Fermi GBM Final Localization
  95. Fermi trigger No 792135758: Global MASTER-Net observations report
  96. EP260131a: VLA detection
  97. GRB 260206A (or XRB from 4U 0513-40): MAXI/GSC detection
  98. GRB 260204A: SVOM/VT confirms fading of the optical afterglow
  99. GRB 260204A: SVOM/VT optical candidate
  100. GRB 260204A : MASTER Global robotic net optical observations

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