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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"

2908 results found.

  1. GRB 071112C: ROTSE-III Confirmation of Optical Counterpart
  2. GRB 071028B Swift-BAT detection of a burst
  3. GRB 071025: Kuiper Telescope Optical Observations
  4. GRB 071025, Swift-BAT refined analysis
  5. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  6. GRB 071013: TNT optical data refined analysis
  7. GRB 071010B: Photometry after 1.6 days
  8. GRB 071010A: Continued Keck Imaging
  9. GRB 071006, Swift-BAT refined analysis
  10. GRB 071010B: Swift detection of a burst
  11. Recent SGR1806-20 Activity
  12. GRB 070917: Swift detection of a bright burst
  13. GRB 070808, Swift-BAT refined analysis
  14. Swift trigger on 4U 1700-377 while star tracker loss-of-lock
  15. GRB 070729, Swift-BAT refined analysis
  16. GRB 070724B: Swift-XRT afterglow likely candidate
  17. GRB 070721A : Faulkes Telescope South optical limit
  18. GRB 070721A, Swift-BAT refined analysis
  19. GRB 070621: Watcher Observations
  20. GRB070520B: optical observations
  21. GRB 070521, optical observation
  22. GRB 070521, Swift-BAT refined analysis
  23. GRB 070521: optical limit by Pi of the Sky
  24. GRB 070419A: RAPTOR Detection of Early Emission
  25. GRB070330: Correction to UVOT position
  26. UVOT observations of GRB070330
  27. GRB 070330, Swift-BAT refined analysis
  28. GRB 070330: Swift-XRT refined analysis
  29. GRB 070330: Swift detection of a burst
  30. GRB 070311: MDM Optical Detection
  31. GRB070227: Swift-XRT refined analysis
  32. VLA observation of GRB 070224
  33. GRB 070227: optical observations
  34. GRB 070227: optical observations
  35. GRB 070209: Swift XRT analysis
  36. GRB 070103: Swift detection of a burst
  37. Retractions of previous Swift-BAT triggers
  38. GRB 061201: Magellan Redshift of nearby Abell cluster
  39. GRB061202 optical limit by "Pi of the Sky"
  40. RHESSI Spectrum of GRB061126
  41. GRB 061126: SARA Observations
  42. GRB 061126: Swift detection of a burst
  43. GRB061122: Swift/UVOT Optical Observations
  44. GRB 061110: Swift detection of a burst
  45. GRB061019: second epoch CrAO observations
  46. GRB 061028: MDM Observations
  47. GRB 061028, Swift-BAT refined analysis
  48. GRB061019: optical observations
  49. GRB 061007: Second Epoch ATCA Radio Observations
  50. GRB 061007: ATCA Radio Observations
  51. GRB060912: Swift/UVOT Observations
  52. GRB060904b optical detections (delayed report due to internet outage)
  53. GRB 060904B: RTT150 optical observations
  54. Two bright bursts from SGR 1806-20 detected with IBAS
  55. GRB 060825: VLA observations
  56. GRB 060825: XRT Team Refined Analysis
  57. GRB 060825: Swift-BAT Refined Analysis
  58. GRB060825: BOOTES-IR optical observations
  59. Konus-Wind observation of GRB 060813
  60. Swift detection of an outburst from the 4U 1246-58 LMXB burster
  61. GRB 060805: Swift detection of a burst
  62. GRB 060801, optical observation
  63. GRB 060605: SkyNet Optical Limits
  64. GRB 060712: Swift detection of a burst
  65. GRB 060502B: A Bright Early-type Galaxy as Putative Host of the Short Burst
  66. GRB 060607: REM NIR afterglow
  67. GRB 060522: Swift detection of a burst with possible optical afterglow
  68. GRB 060516: Swift detection of a burst
  69. GRB060501: P60 imaging and afterglow candidate
  70. GRB060428B, optical observation
  71. GRB060424: optical afterglow detection
  72. GRB 060424: Refined analysis of the Swift-BAT burst
  73. GRB 060403: Swift detection of a burst
  74. GRB 060312: ROTSE-III Optical Limits
  75. Bright short hard GRB 060303: IPN localization and Konus spectrum
  76. GRB 060223B: Swift XRT possible afterglow
  77. GRB 060218/SN 2006aj: RBO optical observations
  78. GRB 060223B: ART optical limits
  79. GRB 060206: Swift/UVOT Observations
  80. GRB 060209(?): Swift-BAT detection of a possible burst
  81. GRB060206: Swift-BAT detection of a burst
  82. GRB060124: detailed XRT analysis
  83. GRB 060123: Swift detection of a very long, faint burst
  84. GRB 060117: PROMPT Observations
  85. GRB 060116: PROMPT Observations
  86. GRB 060105: Radio observations
  87. GRB 060102 - no XRT afterglow
  88. GRB 051210: Swift/UVOT upper limits
  89. GRB051210: Swift UVOT Observation
  90. GRB 051210: Swift detection of a burst
  91. GRB051111: Swift/UVOT Observations
  92. GRB 051111: Swift-BAT refined analysis
  93. GRB051103: MASTER: OT limit and host galaxy candidates
  94. GRB051028: Swift-XRT refined analysis
  95. GRB051105A: Swift/UVOT Observations
  96. GRB051103:_MASTER_optical_observations
  97. GRB051028: WHT optical candidate
  98. GRB051028: Swift XRT Position
  99. SGR 1806-20: continued moderate activity seen with INTEGRAL
  100. GRB051012: Swift-XRT analysis

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