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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. GRB 060714 : Liverpool Telescope Observations
  2. GRB 060714: Swift XRT refined analysis
  3. GRB 060714: OA redshift
  4. GRB 060708: VLT spectroscopy
  5. GRB060708: MARGE low resolution spectrum observations
  6. GRB060714: optical observations
  7. Swift-BAT trigger 219136 is not a GRB
  8. Correction to Circular 5314: Circular refers to GRB 060714
  9. GRB060707 possible optical confirmation
  10. Swift trigger 219136 is probably not a GRB
  11. GRB 060714, optical observation
  12. GRB 060714: Swift detection of a burst with an UVOT optical afterglow
  13. GRB 060605: SkyNet Optical Limits
  14. GRB060712: P60 Observations
  15. GRB 060712: XRT refined analysis
  16. GRB 060712: Swift/UVOT Upper Limits
  17. GRB060526: optical observations
  18. GRB 060712: XRT refined position
  19. GRB 060712: Refined analysis of the Swift-BAT burst
  20. GRB060712: MASTER optical observation
  21. GRB120706: MASTER optical observation
  22. GRB 060712: Swift detection of a burst
  23. Host galaxy of GRB050904: 250 GHz upper limit with MAMBO at the IRAM 30m
  24. GRB 060708: PROMPT Optical Limits
  25. GRB 060707: OA fading and redshift
  26. GRB 060708: Swift-XRT refined analysis
  27. GCN 060708: Swift-UVOT Observations
  28. GRB 060708: Refined analysis of the Swift-BAT burst
  29. GCN 060707: Swift-UVOT observations
  30. GRB 060707: Swift-XRT refined analysis
  31. GRB 060708: Swift detection of a burst with an UVOT countpart
  32. GRB060707 possible optical confirmation
  33. GRB 060707: BOOTES-IR optical afterglow candidate
  34. GRB 060707: Refined analysis of the Swift-BAT burst
  35. GRB 060707: BOOTES-IR optical observation
  36. GRB060614: Possible SN Bump in UVOT U Band Light Curve
  37. GRB 060707: Swift detection of a burst
  38. GRB 060515: Upper Limit on Host Galaxy
  39. GRB 050223: Magellan redshift
  40. GRB 060614: SMARTS host galaxy observations
  41. GRB 060614: Detection of a Possible, Late-Time Rebrightening
  42. Correction to GCN 5278 & GCN 5279 (GRBs 060105 & 060109)
  43. GRB 060109: Upper Limit on Host Galaxy
  44. GRB 060105: Upper limit on Host Galaxy
  45. GRB060614: Detection of the host galaxy but no supernova emission
  46. GRB 060614: redshift confirmation
  47. GRB 060614: Redshift
  48. Swift-BAT trigger 215279 is not a GRB
  49. Trigger 215279: Swift detection of a possible burst (GRB 060619)
  50. GRB060614: Optical observations
  51. GRB 060614: spectroscopy
  52. GRB050326: Host Galaxy Candidates
  53. GRB050124: Possible Host Galaxy
  54. GRB050223: Host Galaxy
  55. GRB060512: near IR observations
  56. GRB060526: optical observations
  57. GRB 060614: pseudo-z from spectral parameters of the prompt emission
  58. Konus-Wind observation of GRB 060614
  59. GRB060605: optical observation
  60. The Unusually Long-Lived Afterglow of GRB 060614
  61. GRB 060614: optical observations
  62. GRB 060605, optical observations
  63. GRB 060614, SMARTS optical/IR afterglow observation
  64. GRB060614: SSO 1m observations
  65. GRB060614: Watcher observation
  66. GRB 060614: Swift-BAT refined analysis
  67. GRB 060614: Swift/UVOT Observations
  68. GRB060614: Swift-XRT refined analysis
  69. GRB 060604, optical observations
  70. GRB 060614: Swift detection of a burst with a bright optical and X-ray counterpart
  71. GRB 060602A: Swift/XRT analysis
  72. BAT Trigger #214277 is SGR 1900+14
  73. GRB 060610: KAIT observations
  74. GRB 060607: RTT150 optical observations
  75. GRB 070706B: Watcher upper limit
  76. GRB 060607B: Swift-BAT Refined Analysis
  77. GRB060602A: Swift/UVOT upper limits
  78. GRB 060607B: Swift detection of a burst
  79. GCN 060607: Swift-UVOT obswervations.
  80. GRB 060607: Swift-BAT Refined Analysis
  81. GRB 060607: optical limit by "Pi of the Sky"
  82. GRB 060607: Swift-XRT Team refined analysis
  83. GRB 060607: IR observations
  84. GRB 060502B: A Bright Early-type Galaxy as Putative Host of the Short Burst
  85. VLT/UVES observations of GRB 060607
  86. GRB 060607: PROMPT Observations
  87. GRB 060605: RTT150 optical observations
  88. GRB 060607: REM NIR afterglow
  89. GRB 060607: Swift detection of a burst with bright optical counterpart
  90. GRB 060522: PROMPT Optical Limits
  91. GRB 060605 BAT refined analysis
  92. GRB 060605: Xinglong TNT optical observations
  93. GRB060602B : REM infrared observations
  94. GRB060605: Swift/UVOT detections
  95. GRB 060605: Swift-XRT Team refined analysis
  96. SALT spectroscopy of GRB 060605
  97. GRB 060605: TNG optical observations
  98. GRB 060605: RTT150 optical observations
  99. GRB060605: Spectral Observations and Redshift
  100. GRB 060605: ROTSE-III Optical Counterpart

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