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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"
  1. AMON Coincidence Alert from the sub-threshold IceCube-HAWC search NuEM-210515A and 210515B
  2. GRB 210514A: update on the BAT trigger time and burst duration
  3. GRB 210514A: Swift detection of a burst
  4. Konus-Wind detection of GRB 210511B
  5. GRB 210512.786: DDOTI Upper Limits on the Afterglow
  6. GRB210510A: Optical afterglow candidate from the Zwicky Transient Facility
  7. Fermi trigger No 642538568: Global MASTER-Net observations report
  8. IceCube-210510A: Upper limits from a search for additional neutrino events in IceCube
  9. IPN triangulation of GRB 210511B
  10. IceCube-210510A: not observable by Fermi-GBM
  11. Short GRB 210323A: likely host galaxy detection
  12. IceCube-210510A: No candidate counterparts from the Zwicky Transient Facility
  13. GRB 210511B: DDOTI Upper Limits on the Afterglow
  14. IPN triangulation of GRB 210427A
  15. GRB 210511B: Fermi GBM observation
  16. Fermi-LAT Gamma-ray Observations of IceCube-210510A
  17. Fermi GRB 210511A: Global MASTER-Net observations report
  18. Fermi GRB 210510A: DDOTI Upper Limits on the Afterglow
  19. Fermi GRB 210511B: Global MASTER-Net observations report
  20. GRB 210511B: AGILE detection
  21. GRB 210511B: GECAM detection
  22. GRB 210511B: BALROG localization (Fermi Trigger 642425204 / GRB 210511477)
  23. GRB 210511B: Fermi GBM Final Real-time Localization
  24. GRB 210511A: Fermi GBM Final Real-time Localization
  25. Fermi GRB 210510A: Global MASTER-Net observations report
  26. GRB 201228B: Swift/BAT-GUANO archival detection and arcminute localization
  27. GRB 200716A: Swift/BAT-GUANO archival detection and arcminute localization
  28. Swift trigger 1047857 is 4U 1700-377
  29. IceCube Alert 210510.20: Global MASTER-Net observations report
  30. GRB 210510A: Fermi GBM Final Real-time Localization
  31. IceCube-210510A: DDOTI Upper Limits
  32. GRB 210509A: RATIR Optical and NIR Upper Limits
  33. GRB 210509A: Swift/UVOT Upper Limits
  34. GRB 210509A: Swift-XRT refined Analysis
  35. IceCube-210510A - IceCube observation of a high-energy neutrino candidate track-like event
  36. GRB 210509A: Swift-BAT refined analysis
  37. Swift GRB 210509A: Global MASTER-Net observations report
  38. GRB 210509A: Enhanced Swift-XRT position
  39. GRB 210509A: BOOTES-4/MET optical upper limit
  40. GRB 210509A: Swift-XRT observations
  41. GRB 210509A: Swift detection of a burst
  42. GRB 210506A: Swift/BAT-GUANO position retraction
  43. IPN triangulation of GRB 210506A
  44. HAWC-210507A: No neutrino counterpart candidates in ANTARES search
  45. Fermi GRB 210507A: Global MASTER-Net observations report
  46. Fermi-LAT Gamma-ray Observations of IceCube-210503A and detection of a new gamma-ray source, Fermi J0931.9+3633
  47. ZTF21aayokph (AT2021lfa): continued Mondy optical observations
  48. GRB 210507A: Fermi GBM Final Real-time Localization
  49. Integral GRB210507.04: Global MASTER-Net observations report
  50. Integral GRB210506.78: Global MASTER-Net observations report
  51. GRB 210506A: Swift-XRT observations
  52. ZTF21aayokph (AT2021lfa): MASTER OT detection 3h befor ZTF
  53. Alert from the HAWC Burst Monitor HAWC-210507A
  54. HAWC GRB 210507.443: DDOTI Upper Limit
  55. GRB 210506A: Nanshan/NEXT optical upper limit
  56. GRB 210506A: TNG NIR upper limits
  57. ZTF21aayokph (AT2021lfa): Mondy and Koshka observatory optical observations
  58. ZTF21aayokph (AT2021lfa): X-ray Detection with Swift/XRT
  59. Lowell Discovery Telescope Observations of ZTF21aayokph (AT2021lfa)
  60. IceCube-210503A: IceCube observation of a high-energy neutrino candidate event
  61. ZTF21aayokph (AT2021lfa): Assy optical observations
  62. GRB 210506A: Swift ToO observations
  63. ZTF21aayokph (AT2021lfa): Nanshan/NEXT optical upper limit
  64. GRB 210506A: Swift/BAT-GUANO detection and possible arcminute localization of a short hard burst
  65. GRB 210504A: Lowell Discovery Telescope optical observations
  66. ZTF21aayokph (AT2021lfa): Redshift from Gemini South
  67. GRB 210504A: VLT X-shooter redshift
  68. GRB 210424B: AstroSat CZTI detection
  69. GRB 210504A: Swift-XRT refined Analysis
  70. RATIR Observations of ZTF21aayokph (AT2021lfa)
  71. DDOTI Observations of ZTF21aayokph (AT2021lfa)
  72. GRB 210504A: Swift-BAT refined analysis
  73. ZTF and LT observations of ZTF21aayokph (AT2021lfa), a fast-fading red transient
  74. GRB 210504A: NOT optical afterglow detection
  75. GRB 210504A: MITSuME Akeno optical upper limits
  76. Fermi GRB 210503A: DDOTI Upper Limits on the Afterglow
  77. GRB 210504A: AST3-3 YaoAn Optical Upper Limit
  78. GRB 210504A: Swift/UVOT Detection
  79. GRB 210504A: BOOTES-4/MET optical upper limit
  80. Swift GRB210504.58: Global MASTER-Net observations report
  81. GRB 210504A: update on the BAT trigger time and burst duration
  82. GRB 210504A: Swift detection of a burst
  83. Fermi GRB 210503A: Global MASTER-Net observations report
  84. GRB 210503A: Fermi GBM Final Real-time Localization
  85. Swift GRB210502.74: Global MASTER-Net observations report
  86. Swift Detection of MAXI J1803-298 including an optical counterpart
  87. MAXI GRB210501.83: Global MASTER-Net observations report
  88. Fermi GRB 210501A: Global MASTER-Net observations report
  89. Fermi trigger No 641601187: Global MASTER-Net observations report
  90. GRB 210430A: BOOTES-1 optical limit
  91. GRB 210424B: MITSuME Akeno optical upper limits
  92. GRB 210501A: Fermi GBM Final Real-time Localization
  93. GRB 210430A: Swift-BAT refined analysis
  94. Fermi GRB 210430B: Global MASTER-Net observations report
  95. GRB 210430B: Fermi GBM Final Real-time Localization
  96. Swift GRB210430.45: Global MASTER-Net observations report
  97. GRB 210430A: Swift detection of a burst
  98. GRB 210424B: CALET Gamma-Ray Burst Monitor detection
  99. GRB 210413B: Swift/UVOT Observations
  100. Konus-Wind detection of GRB 210424B

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