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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. GRB050410 : Null detection report
  2. GRB 050410, optical observations
  3. GRB050410: Radio Observations
  4. GRB 050408: Swift XRT measurement of possible jet break
  5. GRB050410: MASTER optical observations
  6. GRB 050410: Early observations with Swift-UVOT
  7. Swift-BAT detection of GRB 050410
  8. GRB 050410: Swift XRT Position
  9. GRB 050408: Retraction of Proposed Host Galaxy
  10. GRB 050408: Inconsistency of host galaxy identification
  11. GRB 050408: Subaru Observations
  12. GRB 050408: WIDGET simultaneous optical observations
  13. GRB 050408: SOAR UBVRc Observations
  14. GRB 050408: Properties of the Host Galaxy
  15. GRB 050408: Mercator Optical Observations
  16. GRB050408: Radio Observations
  17. GRB 050408: Swift XRT analysis
  18. GRB 050408, SMARTS optical/IR afterglow observations
  19. GRB 050408: Optical limit at 20 min after the burst
  20. GRB 050408, optical observations
  21. GRB 050408: Moderate-resolution Gemini Spectroscopy
  22. GRB 050408,optical observation
  23. GRB 050408 Optical Observations
  24. GRB 050408: Emission and absorption redshift
  25. GRB 050408: Mercator Optical Observations
  26. GRB 050408: Magellan astrometry and photometry
  27. GRB 050408: First Optical observations with TFOSC at the RTT150
  28. GRB 050408: steepening of the optical decay
  29. GRB 050408: Optical afterglow confirmed
  30. GRB 050408: opitcal observation
  31. GRB 050408, optical observations
  32. GRB 050408 optical candidate
  33. GRB 050408: Swift XRT Position
  34. GRB 050408: ROTSE-III Optical Limits
  35. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  36. GRB050408: MASTER optical observations
  37. GRB050401: Radio Detection
  38. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  39. GRB 050406: Magellan optical observations
  40. GRB 050406: early Swift XRT analysis results
  41. GRB 050406 BAT refined analysis
  42. GRB 050406: Early observations with Swift-UVOT
  43. GRB 050406: Swift XRT Position
  44. Swift-BAT detection of GRB 050406
  45. Konus-Wind observation of GRB 050401
  46. GRB050401: Radio observation at 610 MHz with GMRT
  47. GRB 050401: VLT spectroscopic redshift
  48. GRB 050401 Optical Observations
  49. GRB 050401 BAT refined analysis
  50. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  51. GRB050401: TNG R-band observation
  52. GRB 050402A: IR Analysis
  53. GRB 050402A: IR Observations
  54. GRB 050402: Early observations with Swift-UVOT
  55. Swift Trigger 113225: P60 Observations
  56. GRB 050401: Optical afterglow confirmed
  57. GRB 050401: Optical afterglow candidate
  58. Swift-BAT detection of GRB 050401
  59. GRB 050401: Prompt XRT position
  60. Retraction of three Swift GRB triggers
  61. GRB050331: No Afterglow Detected
  62. Swift-BAT detection of GRB 050331b
  63. GRB 050331: Swift UVOT Source
  64. Swift-BAT detection of GRB 050331
  65. GRB 050331: Swift XRT Position
  66. GRB050319: radio observation
  67. Konus-Wind observation of GRB 050326
  68. GRB 050326: Early observations with Swift-UVOT
  69. GRB 050326 XMM-Newton observation
  70. GRB 050326 : Planned XMM-Newton observation
  71. GRB 050326: Swift XRT Position
  72. GRB050326: optical limit 33min before GRB
  73. GRB 050326 BAT refined analysis
  74. GRB050326: delayed XRT observation
  75. Swift-BAT detection of a bright GRB 050326
  76. GRB050319, color indices
  77. GRB050319: RTT150 Optical Observations
  78. Swift-BAT trigger 112060 is not a real GRB
  79. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  80. GRB 050319: ROTSE-III Refined Analysis
  81. GRB 050318: Swift-BAT refined analysis
  82. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  83. GRB050319: VLA Observations
  84. GRB 050319 R band observations
  85. GRB 050319: Swift-UVOT detection of the afterglow
  86. GRB 050315: Variability Analysis of Swift BAT Time History
  87. GRB050319: Radio Observations
  88. GRB 050319: NIR afterglow candidate
  89. GRB 050319:Near IR afterglow
  90. GRB 050318: SWIFT-UVOT refined analysis
  91. GRB 050318: Absorption redshift from Magellan
  92. GRB 050319: Optical observation
  93. GRB 050319 : Confirmation of optical afterglow decay
  94. GRB 050319: Swift-BAT refined analysis
  95. GRB050319,optical observation
  96. Swift Detection of GRB 050319
  97. GRB 050319: Detection of Possible Optical Counterpart
  98. GRB 050318: Swift/UVOT detection of afterglow emission
  99. GRB 050318: Magellan optical afterglow identification
  100. GRB050318: Swift XRT position

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