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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"

19317 results found.

  1. Fermi trigger No 790570272: Global MASTER-Net observations report
  2. EP260119a: Liverpool Telescope optical follow-up observations
  3. GRB 251202A: further radio observations with the VLA
  4. GRB 260120A: Fermi GBM Final Real-time Localization
  5. EP260119a: SVOM/VT optical observation
  6. EP260119a: NOT optical observations
  7. SVOM GRB260119.92: Global MASTER-Net observations report
  8. SVOM GRB260119.92: Global MASTER-Net observations report
  9. SVOM GRB260119.90: Global MASTER-Net observations report
  10. EP260116a: COLIBRÍ detection of a fading optical source
  11. GRB 260117A: Swift-XRT afterglow detection
  12. EP260119a: COLIBRÍ photometric redshift z ≈ 5.6
  13. EP260119a: Global MASTER-Net observations report
  14. GRB 260115A: AstroSat CZTI detection
  15. EP260119a: LCO optical observations
  16. GRB 260117A: ZTSh optical upper limit
  17. EP260119a: COLIBRÍ optical counterpart candidate
  18. EP260119a: preliminary result from the EP-FXT observation
  19. GRB 260110A: SVOM detection of a burst through offline search
  20. EP260119a: EP-WXT detection of a fast X-ray transient
  21. Swift GRB260118.48: Global MASTER-Net observations report
  22. GRB 260117A: SVOM/COLIBRÍ (FM-GFT) optical observations
  23. SVOM GRB260117.82: Global MASTER-Net observations report
  24. Fermi-LAT Gamma-ray Observations of IceCube-260115A
  25. GRB 260117A: SVOM/VT optical candidate
  26. GRB 260117A: SVOM/C-GFT upper limit
  27. GRB 260117A: Swift-XRT observations
  28. GRB 260117A: SVOM detection of a long faint burst
  29. EP 260116a: COLIBRÍ optical upper limit
  30. GRB 260115A: GECAM-B observation
  31. EP260116a: Liverpool Telescope upper limits
  32. FRB 20251229A: Updated CHIME/FRB Baseband Localization of FRB 20251229A
  33. EP260116A: 1.3m DFOT optical upper limit
  34. GRB 260114A: VLT/MUSE spectroscopic observations
  35. IceCube-260115A: Upper limits from a search for additional neutrino events in IceCube
  36. EP260116a: Global MASTER-Net observations report
  37. GRB 260111A: COLIBRÍ fading of the optical counterpart candidate
  38. EP260116a: Xinglong optical upper limit
  39. EP260116a: Einstein Probe detection of an X-ray transient
  40. IceCube Alert 260115.73: Global MASTER-Net observations report
  41. GRB 260115A: BALROG localization (Fermi Trigger 790192010 / GRB 260115741)
  42. IceCube: GCN Notices for high-energy track alerts now streamed via Kafka
  43. Fermi GRB 260115A: Global MASTER-Net observations report
  44. GRB 260115A: Fermi GBM Final Real-time Localization
  45. GRB 251222A: radio detection with the VLA
  46. GRB 260114A: Swift-XRT refined Analysis
  47. GRB 260114A : MITSuME Akeno optical upper limits
  48. GRB 260114A: COLIBRÍ optical upper limits
  49. GRB 260114A: TNG NIR upper limit
  50. GRB 260114A: NOT optical observations
  51. GRB 260114A: SVOM/GRM observation of a short burst
  52. Swift GRB 260114A: Global MASTER-Net observations report
  53. GRB 260114A: GECAM-B observation of a short burst
  54. GRB 260114A: Mondy optical observations
  55. GRB 260114A: Fermi GBM observation
  56. GRB 260112B: GECAM-B observation
  57. GRB 260114A: GMG Optical Observation
  58. Fermi-LAT Gamma-ray Observations of IceCube-260111A
  59. GRB 260114A: Fermi GBM Final Real-time Localization
  60. EP-WXT trigger 01709251266: SVOM/C-GFT confirmation of a stellar flare
  61. IceCube-260111A: Upper limits from a search for additional neutrino events in IceCube
  62. Swift GRB260113.43: Global MASTER-Net observations report
  63. EP260110a: NOT and GTC Optical and Near-Infrared Observations
  64. EP260110a: TRT optical upper limits
  65. Konus-Wind detection of GRB 260101A
  66. GRB 260111A: Swift-XRT observations
  67. GRB 260111A: COLIBRÍ optical afterglow candidate
  68. GRB 260111A: GECAM-B observation of a burst
  69. GRB 260111A: Fermi GBM Observation
  70. The EP-WXT trigger 01709251266 is likely a flaring star
  71. GRB 260111A: GOTO optical upper limits
  72. GRB 260112B: Fermi GBM Final Real-time Localization
  73. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  74. GRB 260112A: Fermi GBM Final Real-time Localization
  75. EP260110a: SVOM/VT optical upper limits
  76. IceCube Alert 260111A: Global MASTER-Net observations report
  77. EP260110a: Global MASTER-Net observations report
  78. Fermi GRB 260111A: Global MASTER-Net observations report
  79. GRB 260111A: Fermi GBM Final Real-time Localization
  80. EP260110a: refined analysis of the EP-WXT and EP-FXT observations
  81. EP 260110a: COLIBRÍ optical observations
  82. EP260110a: SVOM/C-GFT upper limit
  83. EP260110a: Einstein Probe detection of an X-ray transient
  84. GRB 260109C: LCO optical upper limits
  85. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  86. GRB 260109B: Fermi GBM Final Real-time Localization
  87. GRB 260102A: Swift-XRT afterglow detection
  88. GRB 260109A: Fermi GBM Final Real-time Localization
  89. GRB 260104A: Swift-BAT refined analysis
  90. GRB 260101A: Swift-BAT refined analysis
  91. Swift GRB 251230A: Global MASTER-Net OT detection
  92. Fermi GRB 260107A: Global MASTER-Net observations report
  93. GRB 260102A: AbAO optical observations
  94. GRB 260107A: Fermi GBM Final Real-time Localization
  95. EP260105b/EP-WXT trigger 01709251028: Einstein Probe detection of an X-ray transient
  96. The EP-WXT trigger 01709251112 is likely a flaring star
  97. Fermi GRB 260105A: Global MASTER-Net observations report
  98. GRB 260105B: Fermi GBM Detection
  99. EP260105a: FTW optical observations
  100. EP260104a: FTW optical observations

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