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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 060729: Swift/UVOT Detections
  2. GRB 060729: Refined analysis of the Swift-BAT burst
  3. GRB 060729: Swift-XRT refined analysis
  4. GRB 060729 : Planned XMM-Newton observation
  5. GRB 060729: Swift/UVOT Observations
  6. GRB 060729: ROTSE-III Detection of Optical Counterpart
  7. GRB 060729: Swift detection of a burst with an UVOT optical counterpart
  8. GRB 060728: Swift/UVOT Upper Limits
  9. GRB 060728: Refined analysis of the Swift-BAT burst
  10. GRB 060728, SMARTS optical/IR observations
  11. Swift/XRT preliminary analysis
  12. GRB 060728: Swift detection of a burst
  13. GRB060614 ATCA Radio Limits
  14. GRB 060218 (SN 2006aj): IR afterglow detection six months after the
  15. GRB 060714: Swift/UVOT Observations
  16. GRB060719: prompt NIR observations with REM
  17. GRB 060714: NOT observations
  18. GRB 060719: near-infrared afterglow
  19. GRB 060719: correction to the coordinates reported in GCN 5347
  20. GRB 060522: VLA observation
  21. GRB 060719: Swift/UVOT Upper Limits
  22. GRB 060719: VLT/ISAAC observations
  23. GRB 060719: Refined analysis of the Swift-BAT burst
  24. GRB 060719: XRT refined analysis
  25. GRB 060719: further analysis of VLT observations
  26. GRB 060719: optical limit by Pi-of-the-Sky
  27. GRB060719: FRAM early follow-up limit
  28. GRB 060719: prompt PROMPT observations
  29. GRB060719: REM NIR Observations
  30. GRB 060719: Continued LCO optical observations
  31. GRB 060719: VLT observations
  32. GRB 060719: LCO optical observations
  33. GRB 060719: Swift detection of a burst
  34. GRB 060717: Swift XRT refined analysis
  35. GRB 060714: OA fading and a possible host detection
  36. GRB060714: optical observations
  37. GRB 060717: NOT observations
  38. GRB 060714: Refined analysis of the Swift-BAT burst
  39. GRB 060717 optical upper limit
  40. GRB060717: Swift/UVOT upper limits
  41. GRB 060717: Swift XRT refined position
  42. GRB 060717: Swift-BAT refined analysis
  43. GRB060717 - SDSS Pre-burst Observations
  44. GRB 060714: REM infrared observations
  45. GRB 060717, optical observation
  46. GRB 060717: Swift detection of a burst
  47. GRB060714: correction to GCN 5324
  48. GRB060714: optical observations
  49. GRB 060714, SMARTS optical/IR afterglow observation
  50. GRB 060714 : Liverpool Telescope Observations
  51. GRB 060714: Swift XRT refined analysis
  52. GRB 060714: OA redshift
  53. GRB 060708: VLT spectroscopy
  54. GRB060708: MARGE low resolution spectrum observations
  55. GRB060714: optical observations
  56. Swift-BAT trigger 219136 is not a GRB
  57. Correction to Circular 5314: Circular refers to GRB 060714
  58. GRB060707 possible optical confirmation
  59. Swift trigger 219136 is probably not a GRB
  60. GRB 060714, optical observation
  61. GRB 060714: Swift detection of a burst with an UVOT optical afterglow
  62. GRB 060605: SkyNet Optical Limits
  63. GRB060712: P60 Observations
  64. GRB 060712: XRT refined analysis
  65. GRB 060712: Swift/UVOT Upper Limits
  66. GRB060526: optical observations
  67. GRB 060712: XRT refined position
  68. GRB 060712: Refined analysis of the Swift-BAT burst
  69. GRB060712: MASTER optical observation
  70. GRB120706: MASTER optical observation
  71. GRB 060712: Swift detection of a burst
  72. Host galaxy of GRB050904: 250 GHz upper limit with MAMBO at the IRAM 30m
  73. GRB 060708: PROMPT Optical Limits
  74. GRB 060707: OA fading and redshift
  75. GRB 060708: Swift-XRT refined analysis
  76. GCN 060708: Swift-UVOT Observations
  77. GRB 060708: Refined analysis of the Swift-BAT burst
  78. GCN 060707: Swift-UVOT observations
  79. GRB 060707: Swift-XRT refined analysis
  80. GRB 060708: Swift detection of a burst with an UVOT countpart
  81. GRB060707 possible optical confirmation
  82. GRB 060707: BOOTES-IR optical afterglow candidate
  83. GRB 060707: Refined analysis of the Swift-BAT burst
  84. GRB 060707: BOOTES-IR optical observation
  85. GRB060614: Possible SN Bump in UVOT U Band Light Curve
  86. GRB 060707: Swift detection of a burst
  87. GRB 060515: Upper Limit on Host Galaxy
  88. GRB 050223: Magellan redshift
  89. GRB 060614: SMARTS host galaxy observations
  90. GRB 060614: Detection of a Possible, Late-Time Rebrightening
  91. Correction to GCN 5278 & GCN 5279 (GRBs 060105 & 060109)
  92. GRB 060109: Upper Limit on Host Galaxy
  93. GRB 060105: Upper limit on Host Galaxy
  94. GRB060614: Detection of the host galaxy but no supernova emission
  95. GRB 060614: redshift confirmation
  96. GRB 060614: Redshift
  97. Swift-BAT trigger 215279 is not a GRB
  98. Trigger 215279: Swift detection of a possible burst (GRB 060619)
  99. GRB060614: Optical observations
  100. GRB 060614: spectroscopy

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