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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"

16155 results found.

  1. GRB060124: optical observations
  2. GRB060124, BVRcIc field calibration
  3. GRB060124 optical observations
  4. GRB 060121: Probable Detection of NIR Afterglow
  5. GRB060124: optical observation
  6. GRB 060116 HST observations
  7. GRB 060124: HETE detection and spectrum of the main peak
  8. Refined XRT Position for GRB 060123
  9. GRB060124: detailed XRT analysis
  10. GRB 060124 Optical Observations
  11. GRB 060124: ART optical limits during the burst
  12. GRB060123: Optical and IR Imaging
  13. GRB 060124: Keck optical spectrum
  14. GRB 060124: MDM Optical Spectrum
  15. GRB 060124 : Optical observation at Xinglong and Kiso
  16. GRB060124: optical observations at Asiago
  17. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  18. GRB 060121: OHP optical limits
  19. GRB 060124: TAROT optical limits
  20. GRB 060124: Swift/UVOT Observation
  21. GRB 060124: Confirmation of the Afterglow
  22. GRB 060124: XRT position
  23. GRB 060124: Optical Afterglow Candidate from Tautenburg
  24. GRB060124, optical observation
  25. GRB 050124 : Kiso Optical limit
  26. GRB 060124: Optical Observations at Tautenburg
  27. GRB060124:MASTER optical observation
  28. GRB 060116: MARGE optical observations
  29. GRB 060121: Liverpool Telescopes optical limits
  30. GRB 060121: I-band Limits
  31. GRB 060121: Confirmation of Afterglow
  32. GRB 060121: candidate optical counterpart
  33. GRB 060121: optical observations
  34. GRB 060121: optical observations
  35. GRB 060121: Optical imaging
  36. GRB 060121 (=H4010): Results of preliminary spectral analysis
  37. GRB 060121: A bright short/hard GRB localized by HETE-2 SXC
  38. GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
  39. HETE Alert 4006: MASTER promt optical limit
  40. GRB060108: photometric redshift determination
  41. GRB 060117: FRAM refined analysis
  42. GRB 060117: FRAM optical afterglow candidate
  43. GRB 060116: VLT optical observations
  44. GRB060115: REM observations
  45. GRB 060116 : Lulin optical limit
  46. GRB 060116: ROTSE-III Optical Limits
  47. GRB 060115: absorption redshift
  48. GRB 060114: REM observations
  49. GRB 060115: Swift XRT refined analysis
  50. GRB 060115: OT finding chart
  51. GRB060115, optical observation
  52. GRB 060115: MITSuME optical afterglow candidate
  53. GRB060114, optical observation
  54. GRB 060108: IR observations of afterglow
  55. GRB 060108: Evidence for an XRT Position Offset
  56. GRB 060111B: Swift XRT refined analysis
  57. GRB 060111B: MITSuME detection of optical afterglow
  58. GRB 060111B: TAROT optical observation
  59. GRB060111A: RTT150 optical observations
  60. GRB060111B: RTT150, possible host galaxy
  61. GRB 060111B: ROTSE-III Detection of Optical Counterpart Flare
  62. GRB060111.2:_MASTER optical limit
  63. GRB 060111: TAROT optical observation
  64. GRB 060111: ROTSE-III Optical Limits
  65. GRB 060110: Mitsume optical observations
  66. GRB 060110a: RAPTOR detection of early optical emission.
  67. GRB 060110: ROTSE-III Confirmation of Optical Counterpart
  68. GRB060110, optical observation
  69. GRB 060110: Optical observation
  70. GRB 060110: Optical limit
  71. GRB060109, optical observation
  72. GRB060108: P200 Ks Observations
  73. GRB 060108: early UKIRT K-band observations
  74. GRB 060108: a dark burst?
  75. GRB 060108: Mitsume optical observations
  76. GRB060108: Faulkes Telescope observation
  77. GRB060108, optical observation
  78. GRB 060105: Mitsume optical observations
  79. GRB060105, optical observation
  80. GRB060105 : Kiso optical observation
  81. GRB051211B: optical observations
  82. GRB 051221B: Optical Observations with Kuiper 1.54m
  83. GRB 051227: optical observation
  84. GRB 051221A: VLA Radio Observations
  85. GRB051227: Radio Observations
  86. GRB 051227: optical afterglow
  87. GRB 051227: Joint Swift-HETE Spectral Analysis
  88. GRB 051227, optical observation
  89. GRB051117B: optical observation
  90. GRB 051221A: MDM Optical Observations
  91. GRB 051221A: Chandra Afterglow Position
  92. GRB 051221B: ROTSE-III Optical Limits
  93. GRB 051221B: TAROT optical limits
  94. GRB 051221A: WSRT Radio Observations
  95. GRB 051221: Continued fading of optical afterglow
  96. Possible GRB 051221B: MDM Optical Detection
  97. GRB 051221A: RAPTOR Fading Counterpart Constraint
  98. GRB 051221B: BOOTES optical observations.
  99. GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral
  100. GRB 051221: Discovery of fading optical afterglow

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