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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"

36180 results found.

  1. GRB050121: optical observation
  2. GRB050121b: optical observation
  3. GRB 060121: Confirmation of NIR Afterglow
  4. GRB060124: optical observation
  5. GRB060124: optical observations
  6. GRB 060123: Swift refined analysis of an unusual GRB
  7. GRB060124, BVRcIc field calibration
  8. GRB060105: refined analysis of the Suzaku observation
  9. GRB060124 optical observations
  10. GRB 060121: Probable Detection of NIR Afterglow
  11. GRB060124: optical observation
  12. GRB 060116 HST observations
  13. GRB 060124: HETE detection and spectrum of the main peak
  14. Refined XRT Position for GRB 060123
  15. Konus-Wind observation of GRB 060124
  16. GRB060124: detailed XRT analysis
  17. GRB 060124 Optical Observations
  18. GRB 060124: ART optical limits during the burst
  19. GRB060123: Optical and IR Imaging
  20. GRB 060123: P200 Observations
  21. GRB 060124: Keck optical spectrum
  22. GRB 060124: Keck Absorption Redshift
  23. GRB 060124: MDM Optical Spectrum
  24. GRB 060124: XRT refined analysis
  25. GRB 060124: R band Observations
  26. GRB 060124 : Optical observation at Xinglong and Kiso
  27. GRB060124: optical observations at Asiago
  28. GRB 060124: Extremely long burst, Swift-BAT refined analysis
  29. GRB060123: SDSS pre-burst observations
  30. GRB 060123: Swift detection of a very long, faint burst
  31. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  32. GRB 060121: OHP optical limits
  33. GRB 060124: TAROT optical limits
  34. GRB 060124: Swift/UVOT Observation
  35. GRB 060124: Confirmation of the Afterglow
  36. GRB 060124: XRT position
  37. GRB 060124: Optical Afterglow Candidate from Tautenburg
  38. GRB 050124 : Kiso Optical limit
  39. GRB 060124: Optical Observations at Tautenburg
  40. GRB 060117: Suzaku WAM observation of the prompt emission
  41. GRB060124:MASTER optical observation
  42. GRB 060111B: Suzaku WAM observation of the prompt emission
  43. GRB 060124: Swift-BAT detection of a burst
  44. GRB 060116: Radio Detection
  45. GRB 060116: MARGE optical observations
  46. GRB 060121: Swift/UVOT upper limits
  47. GRB 060121: Liverpool Telescopes optical limits
  48. GRB 060121: Swift XRT refined analysis
  49. Konus-Wind observation of GRB 060121
  50. GRB 060121: I-band Limits
  51. GRB 060121: Confirmation of Afterglow
  52. GRB 060121: candidate optical counterpart
  53. GRB 060121: Swift XRT refined position
  54. GRB060121: SARA Observations
  55. GRB 060121: optical observations
  56. GRB 060121: Infrared Observations
  57. GRB 060121: optical observations
  58. GRB 060121: Optical imaging
  59. GRB060121 - SDSS pre-burst observations
  60. GRB 060121: A short-hard GRB in a cluster?
  61. GRB 060121 (=H4010): Results of preliminary spectral analysis
  62. GRB 060121: A bright short/hard GRB localized by HETE-2 SXC
  63. GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
  64. HETE Alert 4006: MASTER promt optical limit
  65. GRB 060117: PROMPT Observations
  66. GRB060117 - ATCA 3/6cm radio limits - correction
  67. GRB060117 - ATCA 3/6cm radio limits
  68. GRB 060116: photometric redshift - the farthest GRB?
  69. GRB 060117: pseudo-z from spectral parameters of the prompt emission
  70. Correction to GCN 4542 on GRB 060117
  71. Konus-Wind observation of GRB 060117
  72. GRB 060116: possible I-J dropout
  73. GRB 060116: UKIRT IR Observations
  74. GRB 060117: Refined analysis of the Swift-BAT burst
  75. GRB 060116: PROMPT Observations
  76. GRB 060117: FRAM refined analysis
  77. GRB 060117: FRAM optical afterglow candidate
  78. GRB 060117: nearby galaxy
  79. GRB 060117: Swift-BAT detection of a bright burst
  80. GRB 060116: VLT optical observations
  81. GRB 060116: Refined analysis of the Swift-BAT burst
  82. GRB 060115: PROMPT Observations
  83. GRB 060116: XRT refined analysis
  84. GRB 060116: IR Candidate Afterglow
  85. GRB 060116: Swift/UVOT upper limits
  86. GRB060115: REM observations
  87. GRB 060110: XRT position and analysis
  88. GRB 060116 : Lulin optical limit
  89. GRB 060116: ROTSE-III Optical Limits
  90. GRB060116: XRT position
  91. GRB060116: Faulkes North observation
  92. GRB 060115: absorption redshift
  93. GRB 060116: Swift-BAT detection of a burst
  94. GRB 060115: Refined analysis of the Swift-BAT burst
  95. GRB 060115: OT photometry with MITSuME
  96. GRB 060115: Swift/UVOT upper limits
  97. GRB 060114: REM observations
  98. GRB 060115: Swift XRT refined analysis
  99. GRB 060115: OT finding chart
  100. GRB 060114: Swift/UVOT Observations

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