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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"

28102 results found.

  1. GRB 260101A: 239Alferov CubeSat detection
  2. EP260116a: COLIBRÍ observations of a tentative optical rebrightening
  3. GRB 260120B: Swift detection of a burst
  4. Swift GRB260120B: Global MASTER-Net observations report
  5. EP260119A: Mondy I-Band Observations
  6. Fermi trigger No 790601190: Global MASTER-Net observations report
  7. Fermi trigger No 790570272: Global MASTER-Net observations report
  8. GRB 260114A: Swift/UVOT Upper Limits
  9. EP260119a: Liverpool Telescope optical follow-up observations
  10. GRB 251202A: further radio observations with the VLA
  11. EP260119a: KAIT optical observations
  12. EP260119a: SVOM/VT optical observation
  13. EP260119a: NOT optical observations
  14. EP260119a: SAO RAS optical observations
  15. SVOM GRB260119.92: Global MASTER-Net observations report
  16. SVOM GRB260119.92: Global MASTER-Net observations report
  17. SVOM GRB260119.90: Global MASTER-Net observations report
  18. EP260116a: COLIBRÍ detection of a fading optical source
  19. GRB 260117A: Swift-XRT afterglow detection
  20. EP260119a: COLIBRÍ photometric redshift z ≈ 5.6
  21. EP260119a: Global MASTER-Net observations report
  22. EP260119a: LCO optical observations
  23. GRB 260117A: ZTSh optical upper limit
  24. EP260119a: COLIBRÍ optical counterpart candidate
  25. EP260119a: EP-WXT detection of a fast X-ray transient
  26. Swift GRB260118.48: Global MASTER-Net observations report
  27. GRB 260117A: SVOM/COLIBRÍ (FM-GFT) optical observations
  28. SVOM GRB260117.82: Global MASTER-Net observations report
  29. Fermi-LAT Gamma-ray Observations of IceCube-260115A
  30. Swift trigger on the HMXB 1A 1118-61
  31. GRB 260117A: SVOM/VT optical candidate
  32. GRB 260117A: SVOM/C-GFT upper limit
  33. GRB 260117A: Swift-XRT observations
  34. GRB 260117A: SVOM detection of a long faint burst
  35. EP 260116a: COLIBRÍ optical upper limit
  36. Swift triggered on the HMXB 1A 1118-61
  37. FRB 20251229A: COLIBRÍ further inspection of the updated localization
  38. EP260116a: Liverpool Telescope upper limits
  39. FRB 20251229A: Updated CHIME/FRB Baseband Localization of FRB 20251229A
  40. EP260116A: 1.3m DFOT optical upper limit
  41. GRB 260114A: VLT/MUSE spectroscopic observations
  42. IceCube-260115A: Upper limits from a search for additional neutrino events in IceCube
  43. EP260116a: Global MASTER-Net observations report
  44. GRB 260111A: COLIBRÍ fading of the optical counterpart candidate
  45. EP260116a: Xinglong optical upper limit
  46. EP260116a: Einstein Probe detection of an X-ray transient
  47. GRB 260114A: VLT/HAWK-I further near-infrared upper limits
  48. IceCube Alert 260115.73: Global MASTER-Net observations report
  49. GRB 260115A: BALROG localization (Fermi Trigger 790192010 / GRB 260115741)
  50. IceCube: GCN Notices for high-energy track alerts now streamed via Kafka
  51. Fermi GRB 260115A: Global MASTER-Net observations report
  52. GRB 251222A: radio detection with the VLA
  53. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  54. GRB 260114A: Swift-XRT refined Analysis
  55. GRB 260114A: VLT/X-shooter redshift of the putative host galaxy
  56. GRB 260114A : MITSuME Akeno optical upper limits
  57. GRB 260114A: COLIBRÍ optical upper limits
  58. GRB 260114A: TNG NIR upper limit
  59. GRB 260114A: NOT optical observations
  60. GRB 260114A: SVOM/GRM observation of a short burst
  61. Swift GRB 260114A: Global MASTER-Net observations report
  62. GRB 260114A: Mondy optical observations
  63. GRB 260114A: GMG Optical Observation
  64. Fermi-LAT Gamma-ray Observations of IceCube-260111A
  65. GRB 260114A: Swift detection of a short burst
  66. EP-WXT trigger 01709251266: SVOM/C-GFT confirmation of a stellar flare
  67. IceCube-260111A: Upper limits from a search for additional neutrino events in IceCube
  68. Swift GRB260113.43: Global MASTER-Net observations report
  69. EP260110a: NOT and GTC Optical and Near-Infrared Observations
  70. EP260110a: TRT optical upper limits
  71. Konus-Wind detection of GRB 260101A
  72. GRB 260111A: Swift-XRT observations
  73. Swift Trigger 1439093: is probably not GRB 260113A
  74. GRB 260111A: COLIBRÍ optical afterglow candidate
  75. GRB 260111A: Fermi GBM Observation
  76. GRB 251230A: Mondy Optical Observations
  77. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  78. IceCube Alert 260111A: Global MASTER-Net observations report
  79. EP260110a: Global MASTER-Net observations report
  80. Fermi GRB 260111A: Global MASTER-Net observations report
  81. Swift trigger 1436759 is not an astrophysical event
  82. EP260110a: KAIT optical upper limit
  83. EP260110a: refined analysis of the EP-WXT and EP-FXT observations
  84. EP 260110a: COLIBRÍ optical observations
  85. EP260110a: SVOM/C-GFT upper limit
  86. EP260110a: Einstein Probe detection of an X-ray transient
  87. GRB 260109C: LCO optical upper limits
  88. GRB 260109C: Kilonova-Catcher optical upper limit
  89. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  90. Swift Trigger 1434591: possible GRB 260109C
  91. GRB 260102A: Swift-XRT afterglow detection
  92. GRB 260104A: Swift-BAT refined analysis
  93. GRB 260101A: Swift-BAT refined analysis
  94. Swift GRB 251230A: Global MASTER-Net OT detection
  95. Fermi GRB 260107A: Global MASTER-Net observations report
  96. GRB 260102A: AbAO optical observations
  97. EP260105b/EP-WXT trigger 01709251028: Einstein Probe detection of an X-ray transient
  98. Fermi GRB 260105A: Global MASTER-Net observations report
  99. GRB 260105B: Fermi GBM Detection
  100. GRB 260105B: BALROG localization (Fermi Trigger 789348101 / GRB 260105973)

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