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

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