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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. GRB060130: REM infrared observations
  2. GRB 060130, SMARTS optical observations
  3. GRB 060130: FRAM optical observations
  4. GRB 060130: further INTEGRAL IBIS results
  5. GRB 060130: a long GRB detected with INTEGRAL
  6. Possible GRB 051221B: MDM Correction
  7. GRB050121: optical observation
  8. GRB050121b: optical observation
  9. GRB 060121: Confirmation of NIR Afterglow
  10. GRB060124: optical observation
  11. GRB060124: optical observations
  12. GRB 060123: Swift refined analysis of an unusual GRB
  13. GRB060124, BVRcIc field calibration
  14. GRB060105: refined analysis of the Suzaku observation
  15. GRB060124 optical observations
  16. GRB 060121: Probable Detection of NIR Afterglow
  17. GRB060124: optical observation
  18. GRB 060116 HST observations
  19. GRB 060124: HETE detection and spectrum of the main peak
  20. Refined XRT Position for GRB 060123
  21. Konus-Wind observation of GRB 060124
  22. GRB060124: detailed XRT analysis
  23. GRB 060124 Optical Observations
  24. GRB 060124: ART optical limits during the burst
  25. GRB060123: Optical and IR Imaging
  26. GRB 060123: P200 Observations
  27. GRB 060124: Keck optical spectrum
  28. GRB 060124: Keck Absorption Redshift
  29. GRB 060124: MDM Optical Spectrum
  30. GRB 060124: XRT refined analysis
  31. GRB 060124: R band Observations
  32. GRB 060124 : Optical observation at Xinglong and Kiso
  33. GRB060124: optical observations at Asiago
  34. GRB 060124: Extremely long burst, Swift-BAT refined analysis
  35. GRB060123: SDSS pre-burst observations
  36. GRB 060123: Swift detection of a very long, faint burst
  37. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  38. GRB 060121: OHP optical limits
  39. GRB 060124: TAROT optical limits
  40. GRB 060124: Swift/UVOT Observation
  41. GRB 060124: Confirmation of the Afterglow
  42. GRB 060124: XRT position
  43. GRB 060124: Optical Afterglow Candidate from Tautenburg
  44. GRB060124, optical observation
  45. GRB 050124 : Kiso Optical limit
  46. GRB 060124: Optical Observations at Tautenburg
  47. GRB 060117: Suzaku WAM observation of the prompt emission
  48. GRB060124:MASTER optical observation
  49. GRB 060111B: Suzaku WAM observation of the prompt emission
  50. GRB 060124: Swift-BAT detection of a burst
  51. GRB 060116: Radio Detection
  52. GRB 060116: MARGE optical observations
  53. GRB 060121: Swift/UVOT upper limits
  54. GRB 060121: Liverpool Telescopes optical limits
  55. GRB 060121: Swift XRT refined analysis
  56. Konus-Wind observation of GRB 060121
  57. GRB 060121: I-band Limits
  58. GRB 060121: Confirmation of Afterglow
  59. GRB 060121: candidate optical counterpart
  60. GRB 060121: Swift XRT refined position
  61. GRB060121: SARA Observations
  62. GRB 060121: optical observations
  63. GRB 060121: Infrared Observations
  64. GRB 060121: optical observations
  65. GRB 060121: Optical imaging
  66. GRB060121 - SDSS pre-burst observations
  67. GRB 060121: A short-hard GRB in a cluster?
  68. GRB 060121 (=H4010): Results of preliminary spectral analysis
  69. GRB 060121: A bright short/hard GRB localized by HETE-2 SXC
  70. GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
  71. HETE Alert 4006: MASTER promt optical limit
  72. GRB 060117: PROMPT Observations
  73. GRB060117 - ATCA 3/6cm radio limits - correction
  74. GRB060117 - ATCA 3/6cm radio limits
  75. GRB 060116: photometric redshift - the farthest GRB?
  76. GRB 060117: pseudo-z from spectral parameters of the prompt emission
  77. Correction to GCN 4542 on GRB 060117
  78. Konus-Wind observation of GRB 060117
  79. GRB 060116: possible I-J dropout
  80. GRB 060116: UKIRT IR Observations
  81. GRB060108: photometric redshift determination
  82. GRB 060117: Refined analysis of the Swift-BAT burst
  83. GRB 060116: PROMPT Observations
  84. GRB 060117: FRAM refined analysis
  85. GRB 060117: FRAM optical afterglow candidate
  86. GRB 060117: nearby galaxy
  87. GRB 060117: Swift-BAT detection of a bright burst
  88. GRB 060116: VLT optical observations
  89. GRB 060116: Refined analysis of the Swift-BAT burst
  90. GRB 060115: PROMPT Observations
  91. GRB 060116: XRT refined analysis
  92. GRB 060116: IR Candidate Afterglow
  93. GRB 060116: Swift/UVOT upper limits
  94. GRB060115: REM observations
  95. GRB 060110: XRT position and analysis
  96. GRB 060116 : Lulin optical limit
  97. GRB 060116: ROTSE-III Optical Limits
  98. GRB060116: XRT position
  99. GRB060116: Faulkes North observation
  100. GRB 060115: absorption redshift

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