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

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