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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"

19550 results found.

  1. Swift-BAT trigger 155764 is probably not a GRB
  2. Swift trigger 155764: bad XRT centroid
  3. Swift-BAT trigger 155535 is definitely not a GRB
  4. GRB050916 : Swift-XRT refined analysis
  5. GRB 050916: XRT position
  6. GRB 050915B: Swift-BAT refined analysis
  7. GRB 050915B: Swift/UVOT Upper Limits
  8. GRB 050915a: IR Transient
  9. GRB 050915B: XRT position
  10. GRB 050915b, SMARTS optical/IR observations
  11. GRB050915B: Swift-BAT detection of a long bright burst
  12. GRB050915: Swift/UVOT upper limits
  13. GRB 050915: IR Observations
  14. GRB 050915: Swift-BAT refined analysis
  15. GRB050915: XRT position
  16. GRB 050915: Swift detection of a GRB
  17. Swift-BAT trigger 155072 is probably not a GRB
  18. GRB 050911: z~0.16 cluster in the field
  19. GRB050911: Swift-BAT detection of a long burst
  20. GRB 050910a: TAROT early optical limits
  21. GRB 050906: Possible X-ray Counterpart
  22. GRB050908: Swift/UVOT Early upper limits
  23. GRB050908 : Swift-XRT refined analysis
  24. GRB 050908: Swift-BAT refined analysis
  25. GRB 050908: Optical observations
  26. GRB 050908: spectroscopic redshift
  27. GRB 050908: Swift detection of a burst
  28. Swift trigger 154073 is not a GRB
  29. GRB 050906: Optical observations at the Very Large Telescope
  30. GRB 050904: Subaru Optical Spectroscopy
  31. GRB 050906: Swift-BAT refined analysis
  32. GRB 050906: Swift XRT upper limit
  33. GRB 050904: Keck I-band Imaging
  34. GRB050906: P60 Observations
  35. GRB 050904: photometric redshift
  36. GRB 050904: Swift/UVOT observations
  37. GRB 050904: NIR object inside the XRT error box
  38. GRB 050904: TAROT optical measurements
  39. GRB050904: Optical Observations
  40. GRB 050904: Environmental Constraints
  41. GRB050904: P60 Observations
  42. GRB 050904: TAROT optical limits
  43. GRB 050827 : OSN 1.5m optical observations
  44. GRB 050827: P200 NIR Observations
  45. GRB050827: Swift/UVOT upper limits
  46. GRB 050827: XRT possible afterglow detection
  47. GRB050824: Maidanak optical limits
  48. Subaru Observations of GRB050724
  49. GRB 050826: Optical Candidate
  50. GRB 050826: BAT refined analysis
  51. GRB050826: Swift/UVOT early upper limits
  52. GRB 050826: Swift XRT position
  53. GRB050826: Swift-BAT detection of a long burst
  54. XRF050509c: Radio upper limits from GMRT
  55. GRB050822: Swift/UVOT upper limits
  56. GRB050813: Maidanak I-band observations
  57. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  58. GRB050820B at FRAM
  59. Swift/UVOT UV Photometry of GRB 050820B
  60. GRB 050822: Swift detection of a long burst
  61. GRB050820a BVRcIc field photometry
  62. GRB050820B XMM-Newton observation
  63. GRB 050820B: Swift XRT position
  64. GRB050820B: Refined analysis of the Swift-BAT burst
  65. GRB050820: refined XRT analysis
  66. GRB 050820: Early RAPTOR detections
  67. GRB050819: refined XRT analysis
  68. GRB 050820: Swift detection of a GRB
  69. GRB050819: Swift XRT position
  70. GRB050819: Swift-BAT detection of a weak burst
  71. GRB 050817: Optical observations
  72. GRB 050814: continued fading
  73. GRB050815: XRT refined analysis
  74. GRB 050815: ROTSE-III Optical Limits
  75. GRB050815: Swift XRT afterglow localization
  76. GRB050815: Swift-BAT detection of a burst
  77. GRB050814: Fading red source
  78. GRB050814: P60 Optical Afterglow Candidate
  79. GRB 050813: Non-fading of afterglow candidate
  80. GRB 050814: XRT refined analysis
  81. GRB050814: SWIFT/UVOT observation
  82. GRB 050814: Swift XRT Afterglow Localization
  83. GRB 050814: Swift detection of a burst
  84. GRB 050813: Magellan detection of a high redshift galaxy cluster
  85. GRB050813, SDSS pre-burst observations
  86. GRB050813: SWIFT/UVOT observation
  87. GRB 050813: Swift XRT afterglow localization
  88. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  89. Detection of an intermediate burst from SGR 1806-20 on August 8
  90. GRB050805b: CrAO optical limit
  91. GRB050803, optical observations
  92. Retraction of Swift Trigger 149131 (GRB 050805B)
  93. GRB 050805b: OHP optical limits
  94. GRB 050805b: TAROT optical limits
  95. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  96. Swift-BAT trigger 149118 is probably not a GRB
  97. GRB050802: TNG optical observations
  98. GRB050803: Radio Observation
  99. GRB 050803: RTT150 optical observations
  100. GRB050801: Radio Observation

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