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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"

32489 results found.

  1. GRB 050408: Retraction of Proposed Host Galaxy
  2. GRB 050408: Inconsistency of host galaxy identification
  3. GRB 050408: Subaru Observations
  4. GRB 050408: WIDGET simultaneous optical observations
  5. GRB 050408: SOAR UBVRc Observations
  6. GRB 050408: Properties of the Host Galaxy
  7. GRB 050408: Mercator Optical Observations
  8. GRB050408: Radio Observations
  9. GRB 050408: Swift XRT analysis
  10. GRB 050408, SMARTS optical/IR afterglow observations
  11. GRB 050408: Optical limit at 20 min after the burst
  12. GRB 050408, optical observations
  13. GRB050408: REM NIR and Optical observation
  14. GRB 050408: Moderate-resolution Gemini Spectroscopy
  15. GRB 050408,optical observation
  16. GRB 050408 Optical Observations
  17. GRB 050408: Emission and absorption redshift
  18. GRB 050408: Mercator Optical Observations
  19. GRB 050408: Magellan astrometry and photometry
  20. GRB 050408: First Optical observations with TFOSC at the RTT150
  21. GRB 050408: steepening of the optical decay
  22. GRB 050408: Optical afterglow confirmed
  23. GRB 050408: opitcal observation
  24. GRB 050408, optical observations
  25. GRB 050408 optical candidate
  26. GRB 050408: Swift XRT Position
  27. GRB 050408: ROTSE-III Optical Limits
  28. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  29. GRB050401: Radio Detection
  30. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  31. GRB 050406: Magellan optical observations
  32. GRB 050406: early Swift XRT analysis results
  33. GRB 050406 BAT refined analysis
  34. GRB 050406: Early observations with Swift-UVOT
  35. GRB 050406: Swift XRT Position
  36. Konus-Wind observation of GRB 050401
  37. GRB050401: Radio observation at 610 MHz with GMRT
  38. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  39. GRB 050401: VLT spectroscopic redshift
  40. GRB 050401 Optical Observations
  41. GRB050401: Maidanak optical observation
  42. GRB 050401 BAT refined analysis
  43. GRB050401: TNG R-band observation
  44. GRB 050402A: IR Analysis
  45. GRB050402: XDSS counterpart
  46. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  47. GRB 050401: Optical afterglow confirmed
  48. Swift-BAT detection of GRB 050401
  49. Retraction of three Swift GRB triggers
  50. GRB050331: No Afterglow Detected
  51. Swift-BAT detection of GRB 050331b
  52. GRB 050331: Swift UVOT Source
  53. Swift-BAT detection of GRB 050331
  54. Swift Data Publicly Available Starting April 5, 2005
  55. GRB050319: radio observation
  56. Konus-Wind observation of GRB 050326
  57. GRB050326: optical limit
  58. GRB 050326: Early observations with Swift-UVOT
  59. GRB 050326 XMM-Newton observation
  60. GRB 050326 : Planned XMM-Newton observation
  61. GRB 050326: Swift XRT Position
  62. GRB050326: optical limit 33min before GRB
  63. GRB 050326 BAT refined analysis
  64. GRB050326: delayed XRT observation
  65. Swift-BAT detection of a bright GRB 050326
  66. GRB050319, optical observations
  67. GRB050319, color indices
  68. GRB050319: optical observation, March 20-22
  69. GRB050319: RTT150 Optical Observations
  70. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  71. GRB 050319: ROTSE-III Refined Analysis
  72. GRB 050318: Swift-BAT refined analysis
  73. GRB050319: VLA Observations
  74. GRB050319: radio observation
  75. GRB 050319 R band observations
  76. GRB 050319: Swift-UVOT detection of the afterglow
  77. GRB 050315: Variability Analysis of Swift BAT Time History
  78. GRB050319: Radio Observations
  79. GRB 050319: NIR afterglow candidate
  80. GRB 050319:Near IR afterglow
  81. GRB050319: BR optical photometry
  82. GRB 050318: SWIFT-UVOT refined analysis
  83. GRB 050318: Absorption redshift from Magellan
  84. GRB 050319: Optical observation
  85. GRB 050319: Swift-BAT refined analysis
  86. GRB050319,optical observation
  87. GRB 050318: Swift/UVOT detection of afterglow emission
  88. GRB 050318: Magellan optical afterglow identification
  89. GRB050318: Swift XRT position
  90. RXTE Observations of GRB050318
  91. GRB 050315, SMARTS optical afterglow decay
  92. GRB050223: analysis of the XMM-Newton observation
  93. GRB050316: MASTER before, simultanious and follow up optical
  94. GRB 050306: ROTSE-III early limits
  95. GRB 050315: Swift-BAT further refined analysis
  96. GRB 050315, SMARTS optical/IR afterglow observations
  97. GRB 050315 I-band observations
  98. GRB050315: Radio afterglow
  99. GRB 050315: Absorption redshift
  100. GRB 050315: Optical afterglow identification

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