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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"
  1. GRB060714: optical observations
  2. Swift-BAT trigger 219136 is not a GRB
  3. Correction to Circular 5314: Circular refers to GRB 060714
  4. GRB060707 possible optical confirmation
  5. Swift trigger 219136 is probably not a GRB
  6. GRB 060714, optical observation
  7. GRB 060714: Swift detection of a burst with an UVOT optical afterglow
  8. GRB 060605: SkyNet Optical Limits
  9. GRB060712: P60 Observations
  10. GRB 060712: XRT refined analysis
  11. GRB 060712: Swift/UVOT Upper Limits
  12. GRB060526: optical observations
  13. GRB 060712: XRT refined position
  14. GRB 060712: Refined analysis of the Swift-BAT burst
  15. GRB060712: MASTER optical observation
  16. GRB120706: MASTER optical observation
  17. GRB 060712: Swift detection of a burst
  18. Host galaxy of GRB050904: 250 GHz upper limit with MAMBO at the IRAM 30m
  19. GRB 060708: PROMPT Optical Limits
  20. GRB 060707: OA fading and redshift
  21. GRB 060708: Swift-XRT refined analysis
  22. GCN 060708: Swift-UVOT Observations
  23. GRB 060708: Refined analysis of the Swift-BAT burst
  24. GCN 060707: Swift-UVOT observations
  25. GRB 060707: Swift-XRT refined analysis
  26. GRB 060708: Swift detection of a burst with an UVOT countpart
  27. GRB060707 possible optical confirmation
  28. GRB 060707: BOOTES-IR optical afterglow candidate
  29. GRB 060707: Refined analysis of the Swift-BAT burst
  30. GRB 060707: BOOTES-IR optical observation
  31. GRB060614: Possible SN Bump in UVOT U Band Light Curve
  32. GRB 060707: Swift detection of a burst
  33. GRB 060515: Upper Limit on Host Galaxy
  34. GRB 050223: Magellan redshift
  35. GRB 060614: SMARTS host galaxy observations
  36. GRB 060614: Detection of a Possible, Late-Time Rebrightening
  37. Correction to GCN 5278 & GCN 5279 (GRBs 060105 & 060109)
  38. GRB 060109: Upper Limit on Host Galaxy
  39. GRB 060105: Upper limit on Host Galaxy
  40. GRB060614: Detection of the host galaxy but no supernova emission
  41. GRB 060614: redshift confirmation
  42. GRB 060614: Redshift
  43. Swift-BAT trigger 215279 is not a GRB
  44. Trigger 215279: Swift detection of a possible burst (GRB 060619)
  45. GRB060614: Optical observations
  46. GRB 060614: spectroscopy
  47. GRB050326: Host Galaxy Candidates
  48. GRB050124: Possible Host Galaxy
  49. GRB050223: Host Galaxy
  50. GRB060512: near IR observations
  51. GRB060526: optical observations
  52. GRB 060614: pseudo-z from spectral parameters of the prompt emission
  53. Konus-Wind observation of GRB 060614
  54. GRB060605: optical observation
  55. The Unusually Long-Lived Afterglow of GRB 060614
  56. GRB 060614: optical observations
  57. GRB 060605, optical observations
  58. GRB 060614, SMARTS optical/IR afterglow observation
  59. GRB060614: SSO 1m observations
  60. GRB060614: Watcher observation
  61. GRB 060614: Swift-BAT refined analysis
  62. GRB 060614: Swift/UVOT Observations
  63. GRB060614: Swift-XRT refined analysis
  64. GRB 060604, optical observations
  65. GRB 060614: Swift detection of a burst with a bright optical and X-ray counterpart
  66. GRB 060602A: Swift/XRT analysis
  67. BAT Trigger #214277 is SGR 1900+14
  68. GRB 060610: KAIT observations
  69. GRB 060607: RTT150 optical observations
  70. GRB 070706B: Watcher upper limit
  71. GRB 060607B: Swift-BAT Refined Analysis
  72. GRB060602A: Swift/UVOT upper limits
  73. GRB 060607B: Swift detection of a burst
  74. GCN 060607: Swift-UVOT obswervations.
  75. GRB 060607: Swift-BAT Refined Analysis
  76. GRB 060607: optical limit by "Pi of the Sky"
  77. GRB 060607: Swift-XRT Team refined analysis
  78. GRB 060607: IR observations
  79. GRB 060502B: A Bright Early-type Galaxy as Putative Host of the Short Burst
  80. VLT/UVES observations of GRB 060607
  81. GRB 060607: PROMPT Observations
  82. GRB 060605: RTT150 optical observations
  83. GRB 060607: REM NIR afterglow
  84. GRB 060607: Swift detection of a burst with bright optical counterpart
  85. GRB 060522: PROMPT Optical Limits
  86. GRB 060605 BAT refined analysis
  87. GRB 060605: Xinglong TNT optical observations
  88. GRB060602B : REM infrared observations
  89. GRB060605: Swift/UVOT detections
  90. GRB 060605: Swift-XRT Team refined analysis
  91. SALT spectroscopy of GRB 060605
  92. GRB 060605: TNG optical observations
  93. GRB 060605: RTT150 optical observations
  94. GRB060605: Spectral Observations and Redshift
  95. GRB 060605: ROTSE-III Optical Counterpart
  96. GRB 060605: Swift detection of a burst with optical counterpart
  97. GRB 060605: ROTSE-III Detection of Optical Counterpart
  98. GRB060604: Swift/UVOT detections
  99. GRB 060604: redshift
  100. GRB 060512: Keck Redshift

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