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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').
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"

18435 results found.

  1. GRB 130215A: ROTSE-III data analysis
  2. Skynet Observations of GRB130215
  3. GRB 130215: ROTSE-III Detection of Optical Counterpart
  4. GRB 130215A: Swift detection of a burst
  5. Swift GRB130206A: late XRT observations.
  6. GRB 130131B: CTIO 0.9-m optical upper-limits
  7. GRB 121128A: optical observations
  8. GRB 121123A: optical observations
  9. GRB 130211A: Swift/UVOT Upper Limits
  10. GRB 130211A: Swift-XRT refined Analysis
  11. GRB 130211A: Swift-BAT refined analysis
  12. GRB 130211A: GROND detection of the afterglow
  13. GRB 130211A: Swift detection of a burst
  14. GRB 130122A: PTF P48 optical upper limits
  15. GRB 130206A: GROND Observations
  16. GRB 130206A: Fermi LAT Observations
  17. GRB 130206A: Fermi GBM observation
  18. GRB 130206A: XRT and UVOT follow-up observations.
  19. GRB 130131B: optical upper limit in Mondy observatory
  20. GRB 130206A, Swift-BAT refined analysis
  21. GRB 130206A: Zadko observatory - Gingin optical observations
  22. Swift GRB 130206A - analysis of Swift/UVOT initial data.
  23. GRB 130206A: Swift-XRT observations
  24. GRB 130131A: optical observation in Mondy observatory
  25. GRB 130206A: Swift detection of a burst
  26. GRB 130131A: Swift/UVOT Upper Limits
  27. GRB 130131A: RAPTOR Limits During Gamma-Ray Emitting Interval
  28. GRB 130131B: Swift-XRT refined Analysis
  29. GRB 130131B: VLT/X-shooter acquisition camera limits
  30. GRB 130131B: GROND Upper limits
  31. GRB 130131A: CARMA 3mm Observations
  32. GRB 130131A: VLA 5.8 Ghz Detection
  33. GRB 130131B: IAC80 I-band observations
  34. GRB 130131B: Swift/UVOT Upper Limits
  35. GRB 130131A: Swift-XRT refined Analysis
  36. GRB 130131B: Enhanced Swift-XRT position
  37. GRB 130131B: Swift-BAT refined analysis
  38. GRB 130131A: Swift-BAT refined analysis
  39. GRB 130131B: TAROT Calern observatory optical observations
  40. GRB 130131B: Zadko observatory - Gingin optical observations
  41. GRB 130131A: Enhanced Swift-XRT position
  42. GRB 130131B: Swift detection of a burst
  43. GRB 130131A - Faulkes Telescope North Observations
  44. GRB 130131A: Swift detection of a burst
  45. Swift/BAT trigger 547142 is new source Swift J1753.7-2544
  46. Swift Trigger 547142: MAXI/GSC upper limit
  47. Swift Trigger 547142: a probable Galactic source
  48. GRB 130122A: CARMA 3mm Observations
  49. GRB 130122A: Swift/UVOT Detection
  50. GRB 130122A: Swift-BAT refined analysis
  51. GRB 130122A: Swift-XRT refined Analysis
  52. GRB 130122A: Enhanced Swift-XRT position
  53. GRB 130122A: MASTER-Net early marginal detection of the OT
  54. GRB 130122A: T100 observations
  55. GRB 130122A: Swift detection of a burst with an optical counterpart
  56. GRB 121225B: Suzaku WAM observation of the prompt emission
  57. GRB 130102A: Swift/UVOT Upper Limits
  58. GRB 130102A: P60 Observations
  59. GRB 130102A: Swift-BAT refined analysis
  60. GRB 130102A: MASTER-Net optical observations
  61. GRB 130102A: Swift-XRT refined Analysis
  62. GRB 130102A: Enhanced Swift-XRT position
  63. GRB 130102A: IAC80 I-band observations
  64. GRB 130102A: Swift detection of a burst
  65. Swift Trigger 544381 is a noise event
  66. GRB 121229A: Swift-XRT refined Analysis
  67. GRB 121229A, Swift-BAT refined analysis
  68. GRB 121229A: Swift/UVOT Upper Limits
  69. GRB 121229A: Enhanced Swift-XRT position
  70. Swift Trigger 544381 is unlikely to be a GRB
  71. GRB 121229A: MAXI/GSC detection
  72. GRB 121229A: GROND detection of the afterglow
  73. GRB 121229A: Swift detection of a burst
  74. GRB 121226A: Swift/UVOT Upper Limits
  75. GRB 121226A: Swift-XRT refined Analysis
  76. GRB 121226A, Swift-BAT refined analysis
  77. GRB 121226A: Optical Observations
  78. GRB 121226A: Zadko observatory - Gingin optical observations
  79. GRB 121226A: BOOTES-4/MET optical observations
  80. GRB 121226A: Swift detection of a burst
  81. Swift-BAT refined analysis of SGR 1E 1841-045 (Trigger=543763)
  82. Trigger 543763: SGR 1E 1841-045: Swift detection of a soft gamma repeater burst (aka Kes 73)
  83. GRB 121217A: Swift-BAT refined analysis
  84. GRB 121217A: Fermi GBM observation
  85. GRB 121217A: Swift-XRT refined Analysis
  86. GRB 121217A: Swift/UVOT Detection
  87. GRB 121217A: GROND Detection of the Afterglow
  88. GRB 121217A: Enhanced Swift-XRT position
  89. GRB 121217A: Swift detection of a burst
  90. GRB 121209A: Swift/UVOT Upper Limits
  91. GRB 121212A: LOAO IzY Observation
  92. GRB 121209A: MAXI/GSC detection
  93. GRB121212A: NOT optical imaging
  94. GRB 121212A: Maidanak optical observations
  95. GRB 121211A: Fermi GBM observation
  96. GRB 121212A: RAPTOR Limits During Gamma-Ray Emitting Interval
  97. GRB 121211A: RAPTOR Limits During Gamma-Ray Emitting Interval
  98. GRB 121212A: PAIRITEL NIR Observations
  99. GRB 121212A: Swift-XRT refined Analysis
  100. GRB 121212A: P60 Observations

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