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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"

2910 results found.

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

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