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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

32763 results found.

  1. GRB 260120A: GECAM-B observation
  2. GRB 260120B: AstroSat CZTI detection
  3. GRB 260114A: Insight-HXMT/HE detection
  4. EP260119a: Assy AZT-20 optical observations
  5. EP260119a: Mondy and SAO RAS optical upper limits
  6. IceCube-260115A: No Candidate Transients from the Zwicky Transient Facility
  7. EP260119a: Xinglong optical upper limit
  8. Fermi GRB 260120C: Global MASTER-Net observations report
  9. GRB 260120B: Swift-BAT refined analysis
  10. EP260116a: COLIBRÍ further observations
  11. GRB 251122A / EP251122a: VLT/X-shooter host redshift z = 1.765
  12. GRB 260120B: Fermi GBM Observation
  13. EP260105a: GTC/HiPERCAM optical observations
  14. GRB 260120B: Swift/UVOT Detection
  15. GRB 260120B: COLIBRÍ optical upper limits
  16. GRB 260120B: SVOM/C-GFT optical counterpart detection
  17. GRB 260101A: 239Alferov CubeSat detection
  18. EP260116a: COLIBRÍ observations of a tentative optical rebrightening
  19. EP260119A: Mondy I-Band Observations
  20. GRB 260114A: Swift/UVOT Upper Limits
  21. EP260119a: Liverpool Telescope optical follow-up observations
  22. GRB 251202A: further radio observations with the VLA
  23. Trigger 1442421: Swift detection of HMXB 1A 1118-61
  24. EP260119A: GTC/OSIRIS+ spectroscopic redshift z = 5.47
  25. EP260119a: KAIT optical observations
  26. EP260119a: SVOM/VT optical observation
  27. EP260119a: update of EP-FXT follow-up observation
  28. EP260119a: NOT optical observations
  29. EP260119a: SAO RAS optical observations
  30. EP260116a: COLIBRÍ detection of a fading optical source
  31. GRB 251208D: SVOM/ECLAIRs refined analysis
  32. GRB 251208D: SVOM/ECLAIRs refined analysis
  33. GRB 260117A: Swift-XRT afterglow detection
  34. EP260119a: COLIBRÍ photometric redshift z ≈ 5.6
  35. EP260119a: Global MASTER-Net observations report
  36. GRB 260115A: AstroSat CZTI detection
  37. EP260119a: LCO optical observations
  38. GRB 260117A: ZTSh optical upper limit
  39. EP260119a: COLIBRÍ optical counterpart candidate
  40. EP260119a: preliminary result from the EP-FXT observation
  41. GRB 260117A: SVOM/COLIBRÍ (FM-GFT) optical observations
  42. Fermi-LAT Gamma-ray Observations of IceCube-260115A
  43. Swift trigger on the HMXB 1A 1118-61
  44. GRB 260117A: SVOM/VT optical candidate
  45. GRB 260117A: SVOM/C-GFT upper limit
  46. GRB 260117A: Swift ToO observations
  47. EP 260116a: COLIBRÍ optical upper limit
  48. GRB 260115A: GECAM-B observation
  49. FRB 20251229A: COLIBRÍ further inspection of the updated localization
  50. EP260116a: Liverpool Telescope upper limits
  51. FRB 20251229A: Updated CHIME/FRB Baseband Localization of FRB 20251229A
  52. EP260116A: 1.3m DFOT optical upper limit
  53. GRB 260114A: VLT/MUSE spectroscopic observations
  54. IceCube-260115A: Upper limits from a search for additional neutrino events in IceCube
  55. EP260116a: Global MASTER-Net observations report
  56. GRB 260111A: COLIBRÍ fading of the optical counterpart candidate
  57. EP260116a: Xinglong optical upper limit
  58. GRB 260114A: VLT/HAWK-I further near-infrared upper limits
  59. IceCube-260115A - IceCube observation of a high-energy neutrino candidate track-like event
  60. IceCube: GCN Notices for high-energy track alerts now streamed via Kafka
  61. Fermi GRB 260115A: Global MASTER-Net observations report
  62. GRB260114A: STEP/T80S optical limits
  63. GRB 251222A: radio detection with the VLA
  64. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  65. Konus-Wind detection of GRB 260114A
  66. GRB 260114A: 6 GHz VLA observations
  67. GRB 260114A: VLT/X-shooter redshift of the putative host galaxy
  68. GRB 260114A : MITSuME Akeno optical upper limits
  69. GRB 260114A: COLIBRÍ optical upper limits
  70. GRB 260114A: TNG NIR upper limit
  71. GRB 260114A: NOT optical observations
  72. Konus-Wind detection of GRB 251230A / EP251230a
  73. GRB 260114A: SVOM/GRM observation of a short burst
  74. Swift GRB 260114A: Global MASTER-Net observations report
  75. GRB 260114A: GECAM-B observation of a short burst
  76. GRB 260114A: Mondy optical observations
  77. GRB 260114A: Fermi GBM observation
  78. GRB 260112B: GECAM-B observation
  79. GRB 260114A: GMG Optical Observation
  80. Fermi-LAT Gamma-ray Observations of IceCube-260111A
  81. EP-WXT trigger 01709251266: SVOM/C-GFT confirmation of a stellar flare
  82. IceCube-260111A: Upper limits from a search for additional neutrino events in IceCube
  83. EP260110a: NOT and GTC Optical and Near-Infrared Observations
  84. EP260110a: TRT optical upper limits
  85. Konus-Wind detection of GRB 260101A
  86. GRB 260111A: Swift-XRT observations
  87. GRB 260111A: COLIBRÍ optical afterglow candidate
  88. GRB 260111A: GECAM-B observation of a burst
  89. GRB 260111A: Fermi GBM Observation
  90. Swift Trigger 1434591 is not a GRB
  91. GRB 260111A: GOTO optical upper limits
  92. GRB 260111A: Swift ToO observations
  93. GRB 251230A: Mondy Optical Observations
  94. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  95. EP260110a: SVOM/VT optical upper limits
  96. EP260110a: Global MASTER-Net observations report
  97. Fermi GRB 260111A: Global MASTER-Net observations report
  98. EP260110a: KAIT optical upper limit
  99. EP260110a: refined analysis of the EP-WXT and EP-FXT observations
  100. EP 260110a: COLIBRÍ optical observations

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