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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"

32491 results found.

  1. GRB 050410: Early observations with Swift-UVOT
  2. Swift-BAT detection of GRB 050410
  3. GRB 050408: Retraction of Proposed Host Galaxy
  4. GRB 050408: Inconsistency of host galaxy identification
  5. GRB 050408: Subaru Observations
  6. GRB 050408: WIDGET simultaneous optical observations
  7. GRB 050408: SOAR UBVRc Observations
  8. GRB 050408: Properties of the Host Galaxy
  9. GRB 050408: Mercator Optical Observations
  10. GRB050408: Radio Observations
  11. GRB 050408: Swift XRT analysis
  12. GRB 050408, SMARTS optical/IR afterglow observations
  13. GRB 050408: Optical limit at 20 min after the burst
  14. GRB 050408, optical observations
  15. GRB050408: REM NIR and Optical observation
  16. GRB 050408: Moderate-resolution Gemini Spectroscopy
  17. GRB 050408,optical observation
  18. GRB 050408 Optical Observations
  19. GRB 050408: Emission and absorption redshift
  20. GRB 050408: Mercator Optical Observations
  21. GRB 050408: Magellan astrometry and photometry
  22. GRB 050408: First Optical observations with TFOSC at the RTT150
  23. GRB 050408: steepening of the optical decay
  24. GRB 050408: Optical afterglow confirmed
  25. GRB 050408: opitcal observation
  26. GRB 050408, optical observations
  27. GRB 050408 optical candidate
  28. GRB 050408: Swift XRT Position
  29. GRB 050408: ROTSE-III Optical Limits
  30. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  31. GRB050401: Radio Detection
  32. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  33. GRB 050406: Magellan optical observations
  34. GRB 050406: early Swift XRT analysis results
  35. GRB 050406 BAT refined analysis
  36. GRB 050406: Early observations with Swift-UVOT
  37. GRB 050406: Swift XRT Position
  38. Konus-Wind observation of GRB 050401
  39. GRB050401: Radio observation at 610 MHz with GMRT
  40. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  41. GRB 050401: VLT spectroscopic redshift
  42. GRB 050401 Optical Observations
  43. GRB050401: Maidanak optical observation
  44. GRB 050401 BAT refined analysis
  45. GRB050401: TNG R-band observation
  46. GRB 050402A: IR Analysis
  47. GRB050402: XDSS counterpart
  48. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  49. GRB 050401: Optical afterglow confirmed
  50. Swift-BAT detection of GRB 050401
  51. Retraction of three Swift GRB triggers
  52. GRB050331: No Afterglow Detected
  53. Swift-BAT detection of GRB 050331b
  54. GRB 050331: Swift UVOT Source
  55. Swift-BAT detection of GRB 050331
  56. Swift Data Publicly Available Starting April 5, 2005
  57. GRB050319: radio observation
  58. Konus-Wind observation of GRB 050326
  59. GRB050326: optical limit
  60. GRB 050326: Early observations with Swift-UVOT
  61. GRB 050326 XMM-Newton observation
  62. GRB 050326 : Planned XMM-Newton observation
  63. GRB 050326: Swift XRT Position
  64. GRB050326: optical limit 33min before GRB
  65. GRB 050326 BAT refined analysis
  66. GRB050326: delayed XRT observation
  67. Swift-BAT detection of a bright GRB 050326
  68. GRB050319, optical observations
  69. GRB050319, color indices
  70. GRB050319: optical observation, March 20-22
  71. GRB050319: RTT150 Optical Observations
  72. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  73. GRB 050319: ROTSE-III Refined Analysis
  74. GRB 050318: Swift-BAT refined analysis
  75. GRB050319: VLA Observations
  76. GRB050319: radio observation
  77. GRB 050319 R band observations
  78. GRB 050319: Swift-UVOT detection of the afterglow
  79. GRB 050315: Variability Analysis of Swift BAT Time History
  80. GRB050319: Radio Observations
  81. GRB 050319: NIR afterglow candidate
  82. GRB 050319:Near IR afterglow
  83. GRB050319: BR optical photometry
  84. GRB 050318: SWIFT-UVOT refined analysis
  85. GRB 050318: Absorption redshift from Magellan
  86. GRB 050319: Optical observation
  87. GRB 050319: Swift-BAT refined analysis
  88. GRB050319,optical observation
  89. GRB 050318: Swift/UVOT detection of afterglow emission
  90. GRB 050318: Magellan optical afterglow identification
  91. GRB050318: Swift XRT position
  92. RXTE Observations of GRB050318
  93. GRB 050315, SMARTS optical afterglow decay
  94. GRB050223: analysis of the XMM-Newton observation
  95. GRB050316: MASTER before, simultanious and follow up optical
  96. GRB 050306: ROTSE-III early limits
  97. GRB 050315: Swift-BAT further refined analysis
  98. GRB 050315, SMARTS optical/IR afterglow observations
  99. GRB 050315 I-band observations
  100. GRB050315: Radio afterglow

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