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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"

19662 results found.

  1. GRB 191019A: MASTER optical observation
  2. GRB 191019A: Swift detection of a burst
  3. GRB 191017B: Swift-BAT refined analysis
  4. GRB 191017B: Swift/UVOT Upper Limits
  5. GRB 191017B: Swift-XRT refined Analysis
  6. GRB 191016A: Swift-XRT afterglow detection
  7. GRB 191016A: Swift/UVOT Detection
  8. GRB 191017B: Enhanced Swift-XRT position
  9. GRB 191017B: Swift detection of a burst
  10. GRB 191016A: early time BOOTES Network and follow-up 1.5m OSN optical observations
  11. GRB 191016A: Swift-BAT refined analysis
  12. GRB 191016A: KAIT Optical Afterglow Confirmation
  13. Swift GRB191016.17: Global MASTER-Net observations report
  14. GRB 191016A: Swift detection of a burst
  15. GRB 191011A: Swift-BAT refined analysis
  16. GRB 191011A: Swift/UVOT Detection
  17. GRB 191011A: RATIR Optical and NIR Observations
  18. GRB 191011A: Fermi GBM observation
  19. GRB 191011A: Swift-XRT refined Analysis
  20. GRB 191011A: Enhanced Swift-XRT position
  21. GRB 191011A: GROND Detection of the Optical/NIR afterglow
  22. GRB 191011A: VLT X-shooter redshift from RRM Observations
  23. Swift GRB191011.19: Global MASTER-Net observations report
  24. Swift GRB191011.19: Global MASTER-Net OT detection
  25. GRB 191011A: Swift detection of a burst with an optical counterpart
  26. LIGO/Virgo S190930t: Continued Swift observations of AT2019sbk
  27. GRB 191004A: CALET Gamma-Ray Burst Monitor detection
  28. GRB 191004B: Swift/UVOT Detection
  29. GRB 191004B: Continued Optical Afterglow Monitoring with LCO
  30. Konus-Wind observation of GRB 191004B
  31. Konus-Wind observation of GRB 191004A
  32. GRB 191004A: Swift/UVOT Detection
  33. GRB 191004A: Optical Detection with LCO
  34. LIGO/Virgo S190930t: Magellan/IMACS imaging of Swift J224718-581442 (AT2019sbk)
  35. LIGO/Virgo S190930t: Swift XRT observations, no secure afterglow found
  36. LIGO/Virgo S190930t: Swift discovery of Swift J224718-581442 (AT2019sbk): a fading UV transient with an X-ray counterpart
  37. LIGO/Virgo S190930t: Swift J221951-484240 optical photometry of Chilescope observatory
  38. LIGO/Virgo S190930t: SALT optical spectroscopy of Swift J221951-484240
  39. GRB 191004B: Swift-XRT refined Analysis
  40. GRB 191004B: GROND Detection of the Optical/NIR Afterglow
  41. GRB 191004A: GROND Upper limits
  42. GRB 191004B: COATLI Optical Observations
  43. GRB 191004A: Swift-XRT refined Analysis
  44. GRB 191004B: VLT/X-shooter redshift
  45. GRB 191004B: Swift-BAT refined analysis
  46. GRB 191004B: NOT optical photometry
  47. GRB 191004A: Swift-BAT refined analysis
  48. GRB 191004A: NOT optical upper limits
  49. GRB 191004B: Enhanced Swift-XRT position
  50. GRB 191004A: Enhanced Swift-XRT position
  51. GRB 191004B: Optical Afterglow Detection with LCO
  52. Swift GRB191004.9: Global MASTER-Net OT detection
  53. GRB 191004B: Swift detection of a burst with an optical counterpart
  54. GRB 191004A: Swift detection of a burst with an optical detection
  55. Swift GRB191004.75: Global MASTER-Net OT detection
  56. GRB 191001A: Swift-XRT observations
  57. LIGO/Virgo S190930t: J-GEM follow-up observation for Swift J221951-484240
  58. GRB 191001B: Optical Upper Limits with LCO
  59. LIGO/Virgo S190930t: Continued Swift/UVOT observations of Swift J221951-484240
  60. GRB 191001B: Swift-BAT refined analysis
  61. IceCube-191001A: Candidate Counterparts with the Zwicky Transient Facility
  62. IPN triangulation of GRB 191001A
  63. GRB 191001A: Swift ToO observations
  64. GRB 191001B: Swift detection of a burst
  65. LIGO/Virgo S190930t: Transient found in Swift/UVOT counterpart search
  66. LIGO/Virgo S190930s: no counterpart candidates in the Swift/BAT observations
  67. LIGO/Virgo S190930t: no counterpart candidates in the Swift/BAT observations
  68. GRB 190926A: AbAO upper optical limit
  69. GRB 190926A: Swift-BAT refined analysis
  70. GRB 190926A: Swift/UVOT Upper Limits
  71. GRB 190926A: KAIT Optical Upper Limit
  72. GRB 190926A: Swift-XRT refined Analysis
  73. GRB 190926A: Enhanced Swift-XRT position
  74. Swift GRB190926.41: Global MASTER-Net observations report
  75. GRB 190926A: Swift detection of a burst
  76. LIGO/Virgo S190923y: no counterpart candidates in the Swift/BAT observations
  77. LIGO/Virgo S190924h: no counterpart candidates in the Swift/BAT observations
  78. GRB 190919B: Swift/UVOT Upper Limits
  79. GRB 190919B: Swift-XRT observations
  80. GRB 190919B: Swift ToO observations
  81. GRB 190828B: AstroSat CZTI detection
  82. LIGO/Virgo S190915ak: no counterpart candidates in the Swift/BAT observations
  83. LIGO/Virgo S190910h: no counterpart candidates in the Swift/BAT observations
  84. LIGO/Virgo S190910d: no counterpart candidates in the Swift/BAT Observations
  85. Swift Trigger 924641 is an outburst from MAXI J1807+132
  86. ZTF19abvizsw: No counterpart candidates from Swift/BAT targeted search
  87. GRB 190823A: Swift-XRT afterglow detection
  88. IPN triangulation of GRB 190906A (short)
  89. GRB190829A: Keck LRIS spectroscopic confirmation of the accompanying supernova
  90. Konus-Wind observation of GRB 190829A
  91. Swift XRT Detection of X-ray Emission from ZTF19abvizsw
  92. GRB 190829A: MASTER confirmation of GROND SN
  93. GRB 190829A: Flattening of optical light curve from continued Liverpool Telescope photometry
  94. LIGO/Virgo S190901ap: no counterpart candidates in the Swift/BAT Observations
  95. GRB 190829A: Continued fading inferred from Liverpool Telescope photometry
  96. GRB 190829A: Liverpool Telescope observations
  97. GRB 190829A: Liverpool Telescope optical photometry
  98. GRB 190829A: MMT detection of the optical afterglow
  99. GRB 190829A: No Neutrino Counterpart detected with ANTARES
  100. GRB 190829A: KAIT Detection of the Optical Afterglow

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