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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 060719: XRT refined analysis
  2. GRB 060719: further analysis of VLT observations
  3. GRB 060719: optical limit by Pi-of-the-Sky
  4. GRB060719: FRAM early follow-up limit
  5. GRB 060719: prompt PROMPT observations
  6. GRB060719: REM NIR Observations
  7. GRB 060719: Continued LCO optical observations
  8. GRB 060719: VLT observations
  9. GRB 060719: LCO optical observations
  10. GRB 060719: Swift detection of a burst
  11. GRB 060717: Swift XRT refined analysis
  12. GRB 060714: OA fading and a possible host detection
  13. GRB060714: optical observations
  14. GRB 060717: NOT observations
  15. GRB 060714: Refined analysis of the Swift-BAT burst
  16. GRB 060717 optical upper limit
  17. GRB060717: Swift/UVOT upper limits
  18. GRB 060717: Swift XRT refined position
  19. GRB 060717: Swift-BAT refined analysis
  20. GRB060717 - SDSS Pre-burst Observations
  21. GRB 060714: REM infrared observations
  22. GRB 060717, optical observation
  23. GRB 060717: Swift detection of a burst
  24. GRB060714: correction to GCN 5324
  25. GRB060714: optical observations
  26. GRB 060714, SMARTS optical/IR afterglow observation
  27. GRB 060714 : Liverpool Telescope Observations
  28. GRB 060714: Swift XRT refined analysis
  29. GRB 060714: OA redshift
  30. GRB 060708: VLT spectroscopy
  31. GRB060708: MARGE low resolution spectrum observations
  32. GRB060714: optical observations
  33. Swift-BAT trigger 219136 is not a GRB
  34. Correction to Circular 5314: Circular refers to GRB 060714
  35. GRB060707 possible optical confirmation
  36. Swift trigger 219136 is probably not a GRB
  37. GRB 060714, optical observation
  38. GRB 060714: Swift detection of a burst with an UVOT optical afterglow
  39. GRB 060605: SkyNet Optical Limits
  40. GRB060712: P60 Observations
  41. GRB 060712: XRT refined analysis
  42. GRB 060712: Swift/UVOT Upper Limits
  43. GRB060526: optical observations
  44. GRB 060712: XRT refined position
  45. GRB 060712: Refined analysis of the Swift-BAT burst
  46. GRB060712: MASTER optical observation
  47. GRB120706: MASTER optical observation
  48. GRB 060712: Swift detection of a burst
  49. Host galaxy of GRB050904: 250 GHz upper limit with MAMBO at the IRAM 30m
  50. GRB 060708: PROMPT Optical Limits
  51. GRB 060707: OA fading and redshift
  52. GRB 060708: Swift-XRT refined analysis
  53. GCN 060708: Swift-UVOT Observations
  54. GRB 060708: Refined analysis of the Swift-BAT burst
  55. GCN 060707: Swift-UVOT observations
  56. GRB 060707: Swift-XRT refined analysis
  57. GRB 060708: Swift detection of a burst with an UVOT countpart
  58. GRB060707 possible optical confirmation
  59. GRB 060707: BOOTES-IR optical afterglow candidate
  60. GRB 060707: Refined analysis of the Swift-BAT burst
  61. GRB 060707: BOOTES-IR optical observation
  62. GRB060614: Possible SN Bump in UVOT U Band Light Curve
  63. GRB 060707: Swift detection of a burst
  64. GRB 060515: Upper Limit on Host Galaxy
  65. GRB 050223: Magellan redshift
  66. GRB 060614: SMARTS host galaxy observations
  67. GRB 060614: Detection of a Possible, Late-Time Rebrightening
  68. Correction to GCN 5278 & GCN 5279 (GRBs 060105 & 060109)
  69. GRB 060109: Upper Limit on Host Galaxy
  70. GRB 060105: Upper limit on Host Galaxy
  71. GRB060614: Detection of the host galaxy but no supernova emission
  72. GRB 060614: redshift confirmation
  73. GRB 060614: Redshift
  74. Swift-BAT trigger 215279 is not a GRB
  75. Trigger 215279: Swift detection of a possible burst (GRB 060619)
  76. GRB060614: Optical observations
  77. GRB 060614: spectroscopy
  78. GRB050326: Host Galaxy Candidates
  79. GRB050124: Possible Host Galaxy
  80. GRB050223: Host Galaxy
  81. GRB060512: near IR observations
  82. GRB060526: optical observations
  83. GRB 060614: pseudo-z from spectral parameters of the prompt emission
  84. Konus-Wind observation of GRB 060614
  85. GRB060605: optical observation
  86. The Unusually Long-Lived Afterglow of GRB 060614
  87. GRB 060614: optical observations
  88. GRB 060605, optical observations
  89. GRB 060614, SMARTS optical/IR afterglow observation
  90. GRB060614: SSO 1m observations
  91. GRB060614: Watcher observation
  92. GRB 060614: Swift-BAT refined analysis
  93. GRB 060614: Swift/UVOT Observations
  94. GRB060614: Swift-XRT refined analysis
  95. GRB 060604, optical observations
  96. GRB 060614: Swift detection of a burst with a bright optical and X-ray counterpart
  97. GRB 060602A: Swift/XRT analysis
  98. BAT Trigger #214277 is SGR 1900+14
  99. GRB 060610: KAIT observations
  100. GRB 060607: RTT150 optical observations

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