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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.

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

26123 results found.

  1. GRB 231024A: AKO Optical Counterpart Candidate
  2. GRB 231028A: CALET Gamma-Ray Burst Monitor detection
  3. GRB 231028A: AstroSat CZTI detection
  4. GRB 231028A: Glowbug gamma-ray detection
  5. GRB 231028A: Fermi GBM Detection
  6. Swift GRB 231028A: Global MASTER-Net observations report
  7. GRB 231028A: Swift detection of a burst
  8. GRB 231025A: Fermi GBM Observation
  9. GRB 231024A: Fermi GBM Observation
  10. GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
  11. GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  12. LIGO/Virgo/KAGRA S231020bw: Upper limits from Swift/BAT-GUANO
  13. GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
  14. GRB 231017A: 1.3m DFOT Optical upper limit
  15. GRB 231018A: Glowbug gamma-ray detection
  16. IPN triangulation of GRB 231018A
  17. GRB 231017A: Swift/UVOT Upper Limit
  18. GRB 230911C: ATCA detection of possible radio counterpart
  19. GRB 231017A: GOTO optical upper limits
  20. GRB 231017A: JinShan optical upper limit
  21. GRB 231018A: GROWTH-India Follow-Up of a Fermi Long GRB
  22. GRB 231017A: Las Cumbres optical upper limit
  23. GRB 231017A: LCOGT Optical Upper Limits
  24. GRB231017A: GROWTH-India upper limits on the optical afterglow
  25. GRB 231017A: Fermi GBM Detection
  26. GRB 231017A: Swift-XRT observations
  27. GRB 231017A: Swift ToO observations
  28. GRB 231017A: Swift/BAT-GUANO candidate arcminute localization of a burst
  29. LIGO/Virgo/KAGRA S231014r: Upper limits from Swift/BAT-GUANO
  30. LIGO/Virgo/KAGRA S231005j: Upper limits from Swift/BAT-GUANO
  31. transient AT2023sva: radio observations with AMI-LA
  32. LIGO/Virgo/KAGRA S231001aq: Upper limits from Swift/BAT-GUANO
  33. LIGO/Virgo/KAGRA S230930al: Upper limits from Swift/BAT-GUANO
  34. LIGO/Virgo/KAGRA S230928cb: Upper limits from Swift/BAT-GUANO
  35. GRB 230827B: 10.4m GTC spectroscopic redshift
  36. NuEm-230927A: Swift-XRT follow-up
  37. AT2023sva / GRB230916B: GIT observations of the afterglow
  38. Swift Triggers 1192745 and 1192747 are not astrophysical events
  39. Swift Triggers 1192740, 1192742 and 1192743 are not astrophysical events
  40. Swift Triggers 1192735 and 1192737 are not astrophysical events
  41. Konus-Wind detection of GRB 230919A
  42. LIGO/Virgo/KAGRA S230924an: Upper limits from Swift/BAT-GUANO
  43. LIGO/Virgo/KAGRA S230920al: Upper limits from Swift/BAT-GUANO
  44. LIGO/Virgo/KAGRA S230919bj: Upper limits from Swift/BAT-GUANO
  45. LIGO/Virgo/KAGRA S230917af: GRAWITA wide-field observations
  46. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  47. GRB 230918B: VLT/X-shooter classification of AT 2023tbf (GOTO23aky) as a dwarf nova
  48. IPN triangulation of GRB 230919A (short)
  49. GRB 230919A: Fermi GBM Observation
  50. Correction to Fermi GBM Statement for Trigger 716527670/230916144
  51. Fermi GBM Statement for Trigger 716527670/230916144
  52. GRB 230919A: Swift/BAT-GUANO detection of a possibly short burst outside the coded FOV
  53. AT2023sva: redshift from OSIRIS+/GTC of the ZTF afterglow
  54. LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
  55. AT 2023sva: NOT observations of the ZTF candidate afterglow
  56. ZTF and SEDM Observations of the Candidate Optical Afterglow AT 2023sva
  57. GRB 230915A: Fermi GBM observation
  58. GRB 230812B: Radio observations with the uGMRT
  59. Swift Triggers 1192480, 1192481, 1192482 and 1192483 are not astrophysical events
  60. GRB 230911A: Fermi GBM Observation
  61. Swift GRB230916.18: Global MASTER-Net observations report
  62. GRB 230915A: Swift/BAT-GUANO detection of a burst
  63. LIGO/Virgo/KAGRA S230914ak: Upper limits from Swift/BAT-GUANO
  64. Swift GRB230916.19: Global MASTER-Net observations report
  65. Swift GRB230916.18: Global MASTER-Net observations report
  66. Swift Triggers 1192234, 1192235 and 1192236 are not astrophysical events
  67. Swift GRB230916.13: Global MASTER-Net observations report
  68. Swift GRB230916.12: Global MASTER-Net observations report
  69. Swift GRB230916.11: Global MASTER-Net observations report
  70. Swift Trigger 1192233 is not a GRB
  71. GRB 230906A: optical counterpart
  72. GRB 230911A: Swift-XRT afterglow detection
  73. GRB 230913A: CALET Gamma-Ray Burst Monitor detection
  74. Swift Trigger 1192088 is not an astrophysical event
  75. GRB 230913A: Glowbug gamma-ray detection
  76. Swift Trigger 1191994 is not an astrophysical event
  77. Swift GRB230913.70: Global MASTER-Net observations report
  78. GRB 230913A: Fermi GBM Observation
  79. Swift Trigger 1191904 is not a GRB
  80. Swift GRB230913.70: Global MASTER-Net observations report
  81. Swift Trigger 1191903 is not an astrophysical event
  82. GRB 230911A: Swift ToO observations
  83. GRB 230913A: Swift/BAT-GUANO arcminute localization of a burst
  84. GRB 230908A: CALET Gamma-Ray Burst Monitor detection
  85. GRB 230911C: Swift-XRT refined Analysis
  86. GRB 230911C: Swift-BAT refined analysis
  87. GRB230911C: BOOTES-6/DPRT optical upper limit
  88. GRB 230906A: Chandra detection of the X-ray afterglow
  89. Swift GRB 230911C: Global MASTER-Net observations report
  90. IPN triangulation of GRB 230911D (long)
  91. GRB 230911D: Fermi-LAT detection
  92. GRB230911C: LCOGT Optical Upper Limits
  93. GRB 230911C: Swift/UVOT Upper Limits
  94. GRB 230911C: GOTO optical upper limits
  95. GRB 230908A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  96. GRB 230911C: Enhanced Swift-XRT position
  97. GRB 230911C: Swift detection of a burst
  98. GRB 230906A: BlackGEM upper limits
  99. GRB 230903A: TESS observations of optical emission
  100. GRB 230906A: Swift/UVOT Upper Limits

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