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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"

12316 results found.

  1. GRB051109B: no UVOT source detected
  2. GRB051105B: REM Optical observation
  3. GRB051105B: Swift/XRT upper limit
  4. GRB051105B: Swift/UVOT upper limit
  5. GRB051103: optical observations
  6. GRB 051103, optical observations
  7. GRB051103: MASTER: OT limit and host galaxy candidates
  8. GRB051105A: Swift/UVOT Observations
  9. GRB051103:_MASTER_optical_observations
  10. GRB 051105b: ART optical limits
  11. GRB 051105B (INTEGRAL 2701): Optical observation
  12. GRB 051105: Optical limit
  13. GRB051028: Swift/UVOT upper limits
  14. GRB051021B: Swift/UVOT Upper limits
  15. GRB051012: Swift-XRT analysis
  16. GRB051021a: optical observations
  17. GRB 051022: Swift/UVOT Upper Limits
  18. GRB 051021: MDM Upper Limit
  19. GRB 051022 (=H3950): SXC Flight Localization is Valid
  20. GRB051021: Swift/UVOT Upper Limits
  21. GRB051021.63
  22. GRB051021.6: MASTER optical observation
  23. GRB 050502b: Optical limit
  24. GRB 051016A: Swift/UVOT upper limits
  25. GRB 051016B: Swift/UVOT detection
  26. GRB 051016: LCO optical and near-IR imaging
  27. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  28. GRB051006: optical observations
  29. GRB 051006: Swift/UVOT Upper Limits
  30. GRB 051008 - a low redshift low-luminosity burst?
  31. GRB051011: MASTER optical observation
  32. GRB051008 - Swift UVOT upper limits
  33. GRB 051008: R-band upper limit
  34. GRB051008: Radio Observation
  35. GRB051001: Swift UVOT Upper Limits
  36. GRB050922B: optical limit
  37. GRB050925: Swift/XRT limits
  38. GRB/SGR 050925: IR Observations
  39. GRB050922C - Swift UVOT preliminary analysis
  40. GRB050925: Swift UVOT upper limits
  41. GRB050922B: Swift UVOT early upper limits.
  42. GRB 050922B: optical limit
  43. HETE Fregate observations of GRB 050922C
  44. GRB 050922A: Analysis of Swift/XRT TOO observation
  45. GRB050916: Swift/UVOT Upper Limits
  46. GRB 050915B: Swift/UVOT Upper Limits
  47. GRB 050915a: IR Transient
  48. GRB050915: Swift/UVOT upper limits
  49. GRB050915: P60 Optical Observations
  50. GRB050911: Upper limit on X-ray afterglow
  51. Swift-BAT trigger 155072 ground analysis
  52. GRB050911: Swift UVOT followup observations
  53. GRB050908: detection of Swift/UVOT optical counterpart
  54. GRB050908: Swift/UVOT Early upper limits
  55. GRB 050906: Swift XRT upper limit
  56. GRB 050904: BOOTES early R-band observation
  57. GRB 050904: Swift/UVOT observations
  58. GRB050827: Swift/UVOT upper limits
  59. Subaru Observations of GRB050724
  60. GRB050826: Swift/UVOT early upper limits
  61. GRB050824: First 2 hours of power low optical decay?
  62. GRB050824: CORRECTION to UVOT observing times
  63. GRB050824: Swift/UVOT detection of fading afterglow
  64. XRF050509c: Radio upper limits from GMRT
  65. GRB050822: Swift/UVOT upper limits
  66. Swift/UVOT UV Photometry of GRB 050820B
  67. GRB 050822: Swift detection of a long burst
  68. Swift/UVOT photometry of GRB050820
  69. GRB050819: Swift-BAT detection of a weak burst
  70. GRB050815: Swift-BAT detection of a burst
  71. GRB050814: SWIFT/UVOT observation
  72. GRB 050814: Swift detection of a burst
  73. GRB050813, SDSS pre-burst observations
  74. GRB050813: SWIFT/UVOT observation
  75. GRB 050813: Possible Short Swift-BAT GRB
  76. GRB050803: Radio Observation
  77. GRB050801: Radio Observation
  78. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  79. GRB050803: Swift-BAT detection of a very long burst
  80. GRB 050730: early TAROT optical observations
  81. Swift/UVOT photometry of GRB050730
  82. GRB 050724: Optical limit
  83. GRB 050724: Swift/UVOT Upper Limit
  84. GRB050714b: Radio Observation
  85. GRB050712: Radio Observations
  86. GRB050713a: Radio Observation
  87. Swift-BAT detection of a possible GRB
  88. Swift/UVOT Observations of GRB 050717
  89. GRB050712: optical limits
  90. Swift detection of GRB 050717
  91. Swift UVOT Observations of GRB 050716
  92. GRB 050716: Optical Observations
  93. GRB050713B :Swift/UVOT observations
  94. GRB 050713A: Swift/UVOT observation
  95. GRB 050713: Swift detection of Bright Burst
  96. GRB 050709: Swift UVOT and XRT observations
  97. GRB 050712: Swift detection of a weak burst
  98. GRB 050626: Swift XRT observations
  99. Swift UVOT observations of GRB 050701
  100. GRB 050607: MDM Observation

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