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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"

28271 results found.

  1. GRB 260117A: SVOM detection of a long faint burst
  2. EP 260116a: COLIBRÍ optical upper limit
  3. Swift triggered on the HMXB 1A 1118-61
  4. FRB 20251229A: COLIBRÍ further inspection of the updated localization
  5. EP260116a: Liverpool Telescope upper limits
  6. FRB 20251229A: Updated CHIME/FRB Baseband Localization of FRB 20251229A
  7. EP260116A: 1.3m DFOT optical upper limit
  8. GRB 260114A: VLT/MUSE spectroscopic observations
  9. IceCube-260115A: Upper limits from a search for additional neutrino events in IceCube
  10. EP260116a: Global MASTER-Net observations report
  11. GRB 260111A: COLIBRÍ fading of the optical counterpart candidate
  12. EP260116a: Xinglong optical upper limit
  13. EP260116a: Einstein Probe detection of an X-ray transient
  14. GRB 260114A: VLT/HAWK-I further near-infrared upper limits
  15. IceCube Alert 260115.73: Global MASTER-Net observations report
  16. GRB 260115A: BALROG localization (Fermi Trigger 790192010 / GRB 260115741)
  17. IceCube: GCN Notices for high-energy track alerts now streamed via Kafka
  18. Fermi GRB 260115A: Global MASTER-Net observations report
  19. GRB 251222A: radio detection with the VLA
  20. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  21. GRB 260114A: Swift-XRT refined Analysis
  22. GRB 260114A: VLT/X-shooter redshift of the putative host galaxy
  23. GRB 260114A : MITSuME Akeno optical upper limits
  24. GRB 260114A: COLIBRÍ optical upper limits
  25. GRB 260114A: TNG NIR upper limit
  26. GRB 260114A: NOT optical observations
  27. GRB 260114A: SVOM/GRM observation of a short burst
  28. Swift GRB 260114A: Global MASTER-Net observations report
  29. GRB 260114A: Mondy optical observations
  30. GRB 260114A: GMG Optical Observation
  31. Fermi-LAT Gamma-ray Observations of IceCube-260111A
  32. GRB 260114A: Swift detection of a short burst
  33. EP-WXT trigger 01709251266: SVOM/C-GFT confirmation of a stellar flare
  34. IceCube-260111A: Upper limits from a search for additional neutrino events in IceCube
  35. Swift GRB260113.43: Global MASTER-Net observations report
  36. EP260110a: NOT and GTC Optical and Near-Infrared Observations
  37. EP260110a: TRT optical upper limits
  38. Konus-Wind detection of GRB 260101A
  39. GRB 260111A: Swift-XRT observations
  40. Swift Trigger 1439093: is probably not GRB 260113A
  41. GRB 260111A: COLIBRÍ optical afterglow candidate
  42. GRB 260111A: Fermi GBM Observation
  43. GRB 251230A: Mondy Optical Observations
  44. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  45. IceCube Alert 260111A: Global MASTER-Net observations report
  46. EP260110a: Global MASTER-Net observations report
  47. Fermi GRB 260111A: Global MASTER-Net observations report
  48. Swift trigger 1436759 is not an astrophysical event
  49. EP260110a: KAIT optical upper limit
  50. EP260110a: refined analysis of the EP-WXT and EP-FXT observations
  51. EP 260110a: COLIBRÍ optical observations
  52. EP260110a: SVOM/C-GFT upper limit
  53. EP260110a: Einstein Probe detection of an X-ray transient
  54. GRB 260109C: LCO optical upper limits
  55. GRB 260109C: Kilonova-Catcher optical upper limit
  56. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  57. Swift Trigger 1434591: possible GRB 260109C
  58. GRB 260102A: Swift-XRT afterglow detection
  59. GRB 260104A: Swift-BAT refined analysis
  60. GRB 260101A: Swift-BAT refined analysis
  61. Swift GRB 251230A: Global MASTER-Net OT detection
  62. Fermi GRB 260107A: Global MASTER-Net observations report
  63. GRB 260102A: AbAO optical observations
  64. EP260105b/EP-WXT trigger 01709251028: Einstein Probe detection of an X-ray transient
  65. Fermi GRB 260105A: Global MASTER-Net observations report
  66. GRB 260105B: Fermi GBM Detection
  67. GRB 260105B: BALROG localization (Fermi Trigger 789348101 / GRB 260105973)
  68. GRB 260105A: SVOM/GRM observation
  69. GRB 260105B: SVOM/GRM observation
  70. FRB 20251229A: COLIBRÍ optical upper limits
  71. Fermi GRB 260105B: Global MASTER-Net observations report
  72. FRB 20251229A: A potentially hyperactive repeating fast radio burst source
  73. EP260105a: refined analysis of the EP-WXT and EP-FXT observations
  74. EP260105a: LCO Optical Upper limit
  75. EP260104a: Global MASTER-Net observations report
  76. EP260104a: Einstein Probe detection of a fast X-ray transient
  77. GRB 260101A: COLIBRÍ optical upper limits
  78. EP260105a: Global MASTER-Net observations report
  79. EP260105a: Einstein Probe detection of an X-ray transient
  80. GRB 260104A: COLIBRÍ optical upper limits
  81. Fermi GRB 260104B: Global MASTER-Net observations report
  82. Swift GRB 260104A: Global MASTER-Net observations report
  83. GRB 251230A/EP-WXT trigger 01709250693: Mephisto optical upper limits
  84. GRB 260104A: Swift-XRT refined Analysis
  85. GRB 260104A: Enhanced Swift-XRT position
  86. GRB 260101A: Swift/UVOT Detection
  87. GRB 260103A: GECAM-B observation of a burst
  88. GRB 260104A: Swift detection of a burst
  89. Fermi-LAT Gamma-ray Observations of IceCube-251225A
  90. GRB 260101A: COLIBRÍ optical observations
  91. SVOM GRB260103.08: Global MASTER-Net observations report
  92. SVOM GRB260102A: Global MASTER-Net observations report
  93. Fermi GBM Sub-Threshold Detection of GRB 260102A
  94. GRB 260102A: EP-FXT follow-up observation
  95. EP260101a: Global MASTER-Net observations report
  96. GRB 260102A: LCO optical upper limits
  97. GRB 260102A: Swift-XRT observations
  98. GRB 260102A: SVOM/COLIBRÍ (FM-GFT) optical observations
  99. GRB 260101A: Fermi GBM Observation
  100. EP260101a: refined analysis of the EP-WXT and EP-FXT observations

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