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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

32512 results found.

  1. Fermi GRB 260930B: Global MASTER-Net observations report
  2. GRB 260926C: SVOM/GRM observation
  3. IceCube-260930A - IceCube observation of a high-energy neutrino candidate track-like event
  4. EP260927a: SVOM/ECLAIRs Upper Limit
  5. GRB 260926C: AstroSat CZTI detection
  6. GRB 260926C: GECAM-B observation
  7. GRB 260926A: GECAM-B observation
  8. EP260927a: Global MASTER-Net observations report
  9. GRB 260926B: Glowbug gamma-ray detection of a likely short burst
  10. GRB 260926A: Glowbug gamma-ray detection
  11. GRB 260924A: VLA detection
  12. GRB 260924A: Swift/UVOT UV grism spectrum results
  13. GRB 260924A: AbAO optical observations
  14. Fermi GRB 260928A: Global MASTER-Net observations report
  15. EP260924a: Global MASTER-Net observations report
  16. GRB 260925A: Swift-BAT refined analysis
  17. Swift Trigger 1513439: consistent with noise and not astrophysical
  18. GRB 260924A: Upper limits from a neutrino search with IceCube
  19. Fermi GRB 260926C: Global MASTER-Net observations report
  20. GRB260914A: MAO/AZT-22 optical observations
  21. Fermi GRB 260926A: Global MASTER-Net observations report
  22. GRB 260924A: Near-infrared detection with MDM/MIRAGE
  23. GRB 260924A: COLIBRÍ optical observations
  24. GRB 260924A: Second-epoch J-band upper limit from the SYSU 80 cm infrared telescope
  25. EP260924a: J-band upper limit by SYSU 80cm infrared telescope
  26. GRB 260925A: J-band upper limit by SYSU 80cm infrared telescope
  27. EP260924a: EP-FXT follow-up observation
  28. GRB 260925A: Swift/UVOT Upper Limits
  29. Konus-Wind detection of GRB 260924A
  30. GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
  31. GRB 260923A: Glowbug gamma-ray detection
  32. GRB 260924A: Optical follow-up observations with Kinder
  33. GRB 260922A: Glowbug gamma-ray detection
  34. GRB 260925A: COLIBRÍ optical upper limits
  35. GRB 260925A: FRAM-Auger optical limit
  36. GRB 260924A: Ondrejov D50 optical afterglow detection
  37. EP260924a: J-band upper limit with WINTER
  38. GRB 260924A: SVOM/GRM observation
  39. GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
  40. GRB 260923A: Insight-HXMT/HE detection
  41. GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
  42. GRB 260924A: Swift/UVOT Detection
  43. GRB 260924A: GROWTH-India Telescope optical observations
  44. GRB 260924A: Swift-BAT refined analysis
  45. GRB 260924A: NuSTAR detection of prompt emission
  46. Konus-Wind detection of GRB 260922A
  47. GRB 260922A: NuSTAR detection of prompt emission
  48. GRB 260921A: NuSTAR detection of prompt emission
  49. Konus-Wind detection of GRB 260921A (correction to GCN 45722)
  50. GRB 260921A: SVOM/GRM observation
  51. GRB 260922A: COLIBRÍ Confirmation of the Optical Counterpart
  52. GRB 260924A: Fermi GRB Observation
  53. Konus-Wind detection of GRB 260921A (possible merger-origin)
  54. GRB 260924A: Fermi-LAT detection of a bright burst
  55. GRB 260924A: AstroSat CZTI detection
  56. GRB 260920A: SVOM/GRM observation
  57. GRB 260924A: NOT optical counterpart confirmation
  58. GRB 260924A: detection of a bright optical afterglow by the 1.5m OSN telescope
  59. GRB 260922A: CALET Gamma-Ray Burst Monitor detection
  60. Fermi GRB 260923A: Global MASTER-Net observations report
  61. Trigger_21914: Swift ToO observations
  62. EP260806a: e-MERLIN detection at 5 GHz
  63. GRB 260922A: Ondrejov D50 optical limit
  64. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  65. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  66. ATCA observations of GRB 260909A
  67. GRB 260922A: Swift-BAT refined analysis
  68. EP260920a: VLT/HAWK-I near-infrared counterpart confirmation
  69. GRB 260922A: J-band upper limit with WINTER
  70. GRB 260922A: Swift/UVOT Upper Limits
  71. GRB 260922A: COLIBRÍ Optical Counterpart Candidate (correction to GCN 45698)
  72. GRB 260922A: COLIBRÍ optical upper limits
  73. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  74. Konus-Wind detection of GRB 260810A
  75. GRB 260920A: Glowbug gamma-ray detection
  76. GRB 260918A: SVOM/ECLAIRs refined analysis
  77. GRB 260922A: SVOM/C-GFT optical upper limit
  78. GRB 260917C: AstroSat CZTI detection
  79. GRB 260920B/EP260920b: GECAM-B detection of a burst
  80. GRB 260921A: AstroSat CZTI detection
  81. GRB 260921A: Swift-BAT refined analysis
  82. GRB 260921A: Fermi GBM Observation
  83. EP260920b: 2.2m CAHA optical afterglow detection and 10.4m GTC redshift confirmation
  84. GRB 260917B:: SVOM/ECLAIRs refined analysis
  85. EP260920a: VLT/HAWK-I near-infrared candidate
  86. Swift GRB 260921A: Global MASTER-Net observations report
  87. EP260920b: VLT/X-shooter spectroscopic redshift z = 3.582
  88. EP260920b: LCO observations
  89. GRB 260920A: AstroSat CZTI detection
  90. EP260920b: SVOM/VT optical observation
  91. EP260920b: refined analysis of the EP-WXT and EP-FXT observations
  92. EP260920b: COLIBRÍ optical observations
  93. EP260920b: LCO optical counterpart detection
  94. EP260920b: Global MASTER-Net observations report
  95. IceCube-260919A: Upper limits from a search for additional neutrino events in IceCube
  96. EP260920a: NOT early time optical upper limits
  97. EP260920a: NOT optical upper limits
  98. EP260920a: SVOM/VT optical upper limits
  99. EP260917a: Global MASTER-Net observations report
  100. EP260920a: refined analysis of the EP-WXT and autonomous EP-FXT observations

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