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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 060728: Swift detection of a burst
  2. GRB060614 ATCA Radio Limits
  3. GRB 060218 (SN 2006aj): IR afterglow detection six months after the
  4. GRB 060714: Swift/UVOT Observations
  5. GRB060719: prompt NIR observations with REM
  6. GRB 060714: NOT observations
  7. GRB 060719: near-infrared afterglow
  8. GRB 060719: correction to the coordinates reported in GCN 5347
  9. GRB 060522: VLA observation
  10. GRB 060719: Swift/UVOT Upper Limits
  11. GRB 060719: VLT/ISAAC observations
  12. GRB 060719: Refined analysis of the Swift-BAT burst
  13. GRB 060719: XRT refined analysis
  14. GRB 060719: further analysis of VLT observations
  15. GRB 060719: optical limit by Pi-of-the-Sky
  16. GRB060719: FRAM early follow-up limit
  17. GRB 060719: prompt PROMPT observations
  18. GRB060719: REM NIR Observations
  19. GRB 060719: Continued LCO optical observations
  20. GRB 060719: VLT observations
  21. GRB 060719: LCO optical observations
  22. GRB 060719: Swift detection of a burst
  23. GRB 060717: Swift XRT refined analysis
  24. GRB 060714: OA fading and a possible host detection
  25. GRB060714: optical observations
  26. GRB 060717: NOT observations
  27. GRB 060714: Refined analysis of the Swift-BAT burst
  28. GRB 060717 optical upper limit
  29. GRB060717: Swift/UVOT upper limits
  30. GRB 060717: Swift XRT refined position
  31. GRB 060717: Swift-BAT refined analysis
  32. GRB060717 - SDSS Pre-burst Observations
  33. GRB 060714: REM infrared observations
  34. GRB 060717, optical observation
  35. GRB 060717: Swift detection of a burst
  36. GRB060714: correction to GCN 5324
  37. GRB060714: optical observations
  38. GRB 060714, SMARTS optical/IR afterglow observation
  39. GRB 060714 : Liverpool Telescope Observations
  40. GRB 060714: Swift XRT refined analysis
  41. GRB 060714: OA redshift
  42. GRB 060708: VLT spectroscopy
  43. GRB060708: MARGE low resolution spectrum observations
  44. GRB060714: optical observations
  45. Swift-BAT trigger 219136 is not a GRB
  46. Correction to Circular 5314: Circular refers to GRB 060714
  47. GRB060707 possible optical confirmation
  48. Swift trigger 219136 is probably not a GRB
  49. GRB 060714, optical observation
  50. GRB 060714: Swift detection of a burst with an UVOT optical afterglow
  51. GRB 060605: SkyNet Optical Limits
  52. GRB060712: P60 Observations
  53. GRB 060712: XRT refined analysis
  54. GRB 060712: Swift/UVOT Upper Limits
  55. GRB060526: optical observations
  56. GRB 060712: XRT refined position
  57. GRB 060712: Refined analysis of the Swift-BAT burst
  58. GRB060712: MASTER optical observation
  59. GRB120706: MASTER optical observation
  60. GRB 060712: Swift detection of a burst
  61. Host galaxy of GRB050904: 250 GHz upper limit with MAMBO at the IRAM 30m
  62. GRB 060708: PROMPT Optical Limits
  63. GRB 060707: OA fading and redshift
  64. GRB 060708: Swift-XRT refined analysis
  65. GCN 060708: Swift-UVOT Observations
  66. GRB 060708: Refined analysis of the Swift-BAT burst
  67. GCN 060707: Swift-UVOT observations
  68. GRB 060707: Swift-XRT refined analysis
  69. GRB 060708: Swift detection of a burst with an UVOT countpart
  70. GRB060707 possible optical confirmation
  71. GRB 060707: BOOTES-IR optical afterglow candidate
  72. GRB 060707: Refined analysis of the Swift-BAT burst
  73. GRB 060707: BOOTES-IR optical observation
  74. GRB060614: Possible SN Bump in UVOT U Band Light Curve
  75. GRB 060707: Swift detection of a burst
  76. GRB 060515: Upper Limit on Host Galaxy
  77. GRB 050223: Magellan redshift
  78. GRB 060614: SMARTS host galaxy observations
  79. GRB 060614: Detection of a Possible, Late-Time Rebrightening
  80. Correction to GCN 5278 & GCN 5279 (GRBs 060105 & 060109)
  81. GRB 060109: Upper Limit on Host Galaxy
  82. GRB 060105: Upper limit on Host Galaxy
  83. GRB060614: Detection of the host galaxy but no supernova emission
  84. GRB 060614: redshift confirmation
  85. GRB 060614: Redshift
  86. Swift-BAT trigger 215279 is not a GRB
  87. Trigger 215279: Swift detection of a possible burst (GRB 060619)
  88. GRB060614: Optical observations
  89. GRB 060614: spectroscopy
  90. GRB050326: Host Galaxy Candidates
  91. GRB050124: Possible Host Galaxy
  92. GRB050223: Host Galaxy
  93. GRB060512: near IR observations
  94. GRB060526: optical observations
  95. GRB 060614: pseudo-z from spectral parameters of the prompt emission
  96. Konus-Wind observation of GRB 060614
  97. GRB060605: optical observation
  98. The Unusually Long-Lived Afterglow of GRB 060614
  99. GRB 060614: optical observations
  100. GRB 060605, optical observations

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