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

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