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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: near-infrared afterglow
  2. GRB 060719: correction to the coordinates reported in GCN 5347
  3. GRB 060522: VLA observation
  4. GRB 060719: Swift/UVOT Upper Limits
  5. GRB 060719: VLT/ISAAC observations
  6. GRB 060719: Refined analysis of the Swift-BAT burst
  7. GRB 060719: XRT refined analysis
  8. GRB 060719: further analysis of VLT observations
  9. GRB 060719: optical limit by Pi-of-the-Sky
  10. GRB060719: FRAM early follow-up limit
  11. GRB 060719: prompt PROMPT observations
  12. GRB060719: REM NIR Observations
  13. GRB 060719: Continued LCO optical observations
  14. GRB 060719: VLT observations
  15. GRB 060719: LCO optical observations
  16. GRB 060719: Swift detection of a burst
  17. GRB 060717: Swift XRT refined analysis
  18. GRB 060714: OA fading and a possible host detection
  19. GRB060714: optical observations
  20. GRB 060717: NOT observations
  21. GRB 060714: Refined analysis of the Swift-BAT burst
  22. GRB 060717 optical upper limit
  23. GRB060717: Swift/UVOT upper limits
  24. GRB 060717: Swift XRT refined position
  25. GRB 060717: Swift-BAT refined analysis
  26. GRB060717 - SDSS Pre-burst Observations
  27. GRB 060714: REM infrared observations
  28. GRB 060717, optical observation
  29. GRB 060717: Swift detection of a burst
  30. GRB060714: correction to GCN 5324
  31. GRB060714: optical observations
  32. GRB 060714, SMARTS optical/IR afterglow observation
  33. GRB 060714 : Liverpool Telescope Observations
  34. GRB 060714: Swift XRT refined analysis
  35. GRB 060714: OA redshift
  36. GRB 060708: VLT spectroscopy
  37. GRB060708: MARGE low resolution spectrum observations
  38. GRB060714: optical observations
  39. Swift-BAT trigger 219136 is not a GRB
  40. Correction to Circular 5314: Circular refers to GRB 060714
  41. GRB060707 possible optical confirmation
  42. Swift trigger 219136 is probably not a GRB
  43. GRB 060714, optical observation
  44. GRB 060714: Swift detection of a burst with an UVOT optical afterglow
  45. GRB 060605: SkyNet Optical Limits
  46. GRB060712: P60 Observations
  47. GRB 060712: XRT refined analysis
  48. GRB 060712: Swift/UVOT Upper Limits
  49. GRB060526: optical observations
  50. GRB 060712: XRT refined position
  51. GRB 060712: Refined analysis of the Swift-BAT burst
  52. GRB060712: MASTER optical observation
  53. GRB120706: MASTER optical observation
  54. GRB 060712: Swift detection of a burst
  55. Host galaxy of GRB050904: 250 GHz upper limit with MAMBO at the IRAM 30m
  56. GRB 060708: PROMPT Optical Limits
  57. GRB 060707: OA fading and redshift
  58. GRB 060708: Swift-XRT refined analysis
  59. GCN 060708: Swift-UVOT Observations
  60. GRB 060708: Refined analysis of the Swift-BAT burst
  61. GCN 060707: Swift-UVOT observations
  62. GRB 060707: Swift-XRT refined analysis
  63. GRB 060708: Swift detection of a burst with an UVOT countpart
  64. GRB060707 possible optical confirmation
  65. GRB 060707: BOOTES-IR optical afterglow candidate
  66. GRB 060707: Refined analysis of the Swift-BAT burst
  67. GRB 060707: BOOTES-IR optical observation
  68. GRB060614: Possible SN Bump in UVOT U Band Light Curve
  69. GRB 060707: Swift detection of a burst
  70. GRB 060515: Upper Limit on Host Galaxy
  71. GRB 050223: Magellan redshift
  72. GRB 060614: SMARTS host galaxy observations
  73. GRB 060614: Detection of a Possible, Late-Time Rebrightening
  74. Correction to GCN 5278 & GCN 5279 (GRBs 060105 & 060109)
  75. GRB 060109: Upper Limit on Host Galaxy
  76. GRB 060105: Upper limit on Host Galaxy
  77. GRB060614: Detection of the host galaxy but no supernova emission
  78. GRB 060614: redshift confirmation
  79. GRB 060614: Redshift
  80. Swift-BAT trigger 215279 is not a GRB
  81. Trigger 215279: Swift detection of a possible burst (GRB 060619)
  82. GRB060614: Optical observations
  83. GRB 060614: spectroscopy
  84. GRB050326: Host Galaxy Candidates
  85. GRB050124: Possible Host Galaxy
  86. GRB050223: Host Galaxy
  87. GRB060512: near IR observations
  88. GRB060526: optical observations
  89. GRB 060614: pseudo-z from spectral parameters of the prompt emission
  90. Konus-Wind observation of GRB 060614
  91. GRB060605: optical observation
  92. The Unusually Long-Lived Afterglow of GRB 060614
  93. GRB 060614: optical observations
  94. GRB 060605, optical observations
  95. GRB 060614, SMARTS optical/IR afterglow observation
  96. GRB060614: SSO 1m observations
  97. GRB060614: Watcher observation
  98. GRB 060614: Swift-BAT refined analysis
  99. GRB 060614: Swift/UVOT Observations
  100. GRB060614: Swift-XRT refined analysis

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