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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"

28097 results found.

  1. GRB 260922A: COLIBRÍ optical upper limits
  2. GRB 260922A: Swift-XRT refined Analysis
  3. GRB 260922A: Enhanced Swift-XRT position
  4. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  5. GRB 260920A: Glowbug gamma-ray detection
  6. GRB 260922A: SVOM/C-GFT optical upper limit
  7. GRB 260922A: Swift detection of a burst
  8. GRB 260921A: AstroSat CZTI detection
  9. GRB 260921A: Swift-BAT refined analysis
  10. GRB 260921A: Fermi GBM Observation
  11. EP Alert 260921.58: Global MASTER-Net observations report
  12. GRB 260917B:: SVOM/ECLAIRs refined analysis
  13. The EP-WXT trigger 01709319528 is likely a flaring star
  14. EP260920a: VLT/HAWK-I near-infrared candidate
  15. Swift GRB 260921A: MASTER OT J094129.58+025052.5 possible optical counterpart detection with host galaxy (z=1.3)
  16. Swift GRB 260921A: Global MASTER-Net observations report
  17. GRB 260921A: Swift detection of a burst
  18. EP260920b: LCO observations
  19. EP260920b: SVOM/VT optical observation
  20. EP260920b: refined analysis of the EP-WXT and EP-FXT observations
  21. EP260920b: COLIBRÍ optical observations
  22. EP260920b: LCO optical counterpart detection
  23. EP Alert 260921.01: Global MASTER-Net observations report
  24. EP260920b: Global MASTER-Net observations report
  25. EP260920b: Einstein Probe detection of an X-ray transient
  26. IceCube-260919A: Upper limits from a search for additional neutrino events in IceCube
  27. EP Alert 260920.66: Global MASTER-Net observations report
  28. EP-WXT detected a brightening of HMXB LS V +44 17
  29. EP260920a: NOT early time optical upper limits
  30. EP260920a: NOT optical upper limits
  31. EP260920a: SVOM/VT optical upper limits
  32. EP260917a: Global MASTER-Net observations report
  33. EP260920a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  34. EP260920a: COLIBRÍ optical upper limits
  35. EP260917b: EP-FXT non-detection and upper limit
  36. IceCube Alert 260919A: Global MASTER-Net observations report
  37. EP260920a: LCO optical counterpart candidate
  38. EP260920a: Einstein Probe detection of an X-ray transient
  39. EP Alert 260919.40: Global MASTER-Net observations report
  40. GRB 260915A: VLT optical and near-infrared upper limits
  41. EP260917a: SVOM/VT optical upper limits
  42. GRB 260918A: SVOM/C-GFT optical upper limits
  43. EP Alert 260918.62: Global MASTER-Net observations report
  44. Fermi GBM Sub-Threshold Detection of GRB 260918A
  45. EP Alert 260918.24: Global MASTER-Net observations report
  46. SVOM GRB260918.16: Global MASTER-Net observations report
  47. GRB 260916B: Glowbug gamma-ray detection of a short burst
  48. GRB 260918A: EP-FXT follow-up observation
  49. GRB 260917B: Mondy optical upper limit
  50. EP260917b: EP-WXT detection of an X-ray transient
  51. EP260917A: J-band upper limit with WINTER
  52. EP Alert 260917.32: Global MASTER-Net observations report
  53. GRB 260917B: EP-FXT follow-up observation
  54. EP260917a: COLIBRÍ optical upper limits
  55. GRB 260915A: Swift-XRT afterglow detection
  56. GRB 260918A: LCO optical upper limits
  57. EP260917a: Einstein Probe detection of an X-ray transient
  58. GRB 260918A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  59. GRB 260918A: SVOM detection of a burst
  60. GRB 260917B: FRAM-Auger optical limits
  61. GRB 260916B: Fermi GBM Detection
  62. IceCube-260916A: Upper limits from a search for additional neutrino events in IceCube
  63. GRB 260917A: Glowbug gamma-ray detection
  64. GRB 260915A: SVOM/ECLAIRs refined analysis
  65. GRB 260917B: WINTER J-band observations
  66. GRB 260917B: SVOM/VT optical observations
  67. SVOM GRB260917.16: Global MASTER-Net observations report
  68. GRB 260917B: LCO optical observation
  69. GRB 260917B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  70. GRB 260917B: SVOM detection of a faint burst
  71. GRB 260917A: BALROG localization (Fermi Trigger 811304653 / GRB 260917100)
  72. Fermi trigger No 811304653: Global MASTER-Net observations report
  73. GRB 260915A: J-band upper limit with WINTER
  74. Fermi trigger No 811264269: Global MASTER-Net observations report
  75. GRB 260909A: NOEMA detection
  76. GRB 260914A: Mondy and TShAO optical observations
  77. GRB 260914A: SVOM/ECLAIRs refined analysis
  78. GRB 260909A: Swift-XRT observations
  79. GRB 260916A: MAXI/GSC detection
  80. MAXI GRB260916.37: Global MASTER-Net observations report
  81. GRB 260915A: J-band upper limit by SYSU 80cm infrared telescope
  82. GRB 260915A: SVOM/C-GFT optical upper limits
  83. GRB 260915A: EP-FXT follow-up observation
  84. GRB 260915A: SVOM/VT refined early optical upper limits
  85. GRB 260915A: REM optical/NIR observations
  86. GRB 260914A: REM optical/NIR observations
  87. GRB 260914A: VLT/X-shooter observations and redshift confirmation
  88. GRB 260915A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  89. GRB 260915A: NOT optical upper limit
  90. SVOM GRB260915.05: Global MASTER-Net observations report
  91. GRB 260915A: SVOM/VT optical upper limits from VHF data
  92. Fermi GBM Sub-Threshold Detection of GRB 260915A
  93. GRB 260915A: LCO optical upper limits
  94. EP Alert 260914.53: Global MASTER-Net observations report
  95. GRB 260914A: EP-FXT follow-up observation
  96. GRB 260915A: SVOM detection of a burst
  97. Fermi GBM Sub-Threshold Detection of GRB 260914A
  98. GRB 260914A: LCO optical observation
  99. GRB 260914A: SVOM/C-GFT optical observations
  100. GRB 260914A: SVOM/VT optical observation from VHF data

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