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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"

36804 results found.

  1. GRB 050412: optical limit
  2. GRB 050412: optical observations
  3. GRB 050408: refined XRT analysis, no jet break seen yet
  4. GRB 050412: early Swift XRT analysis results
  5. GRB 050412 : XingLong optical observation
  6. GRB 050412: Swift-BAT refined analysis
  7. GRB 050412: ANU 2.3m observations
  8. GRB 050412: Early Optical/Ultraviolet Observations with
  9. GRB 050412: retraction of UVOT transient report
  10. GRB 050412: UVOT transient not in XRT error circle
  11. GRB 050408: SDSS Field Calibration
  12. GRB 050412: Optical limit
  13. GRB 050412: LCO Optical Observations
  14. GRB 050412: Optical observations
  15. GRB050412: P60 Observations
  16. GRB 050412: Swift XRT Position
  17. GRB050412: optical limit before and during GRB
  18. GRB 050412: LCO optical observations
  19. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  20. GRB 050412: IR and Optical observations
  21. GRB 050412: IR Observations
  22. GRB050408: Radio Observations
  23. GRB 050401: Optical limit
  24. GRB 050408: Optical limit
  25. GRB050410: P60 Observations
  26. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  27. GRB 050410, optical observations
  28. GRB 050408: PROMPT VRcIc Observations
  29. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  30. GRB 050410 R band Optical Observations
  31. GRB050410 : Null detection report
  32. GRB 050410, optical observations
  33. GRB050410: Radio Observations
  34. GRB 050408: Swift XRT measurement of possible jet break
  35. GRB050410: MASTER optical observations
  36. GRB 050410: Early observations with Swift-UVOT
  37. Swift-BAT detection of GRB 050410
  38. GRB 050410: Swift XRT Position
  39. GRB 050408: Retraction of Proposed Host Galaxy
  40. GRB 050408: Inconsistency of host galaxy identification
  41. GRB 050408: Subaru Observations
  42. GRB 050408: WIDGET simultaneous optical observations
  43. GRB 050408: SOAR UBVRc Observations
  44. GRB 050408: Properties of the Host Galaxy
  45. GRB 050408: Mercator Optical Observations
  46. GRB050408: Radio Observations
  47. GRB 050408: Swift XRT analysis
  48. GRB 050408, SMARTS optical/IR afterglow observations
  49. GRB 050408: Optical limit at 20 min after the burst
  50. GRB 050408, optical observations
  51. GRB 050408: Moderate-resolution Gemini Spectroscopy
  52. GRB 050408,optical observation
  53. GRB 050408 Optical Observations
  54. GRB 050408: Emission and absorption redshift
  55. GRB 050408: Mercator Optical Observations
  56. GRB 050408: Magellan astrometry and photometry
  57. GRB 050408: First Optical observations with TFOSC at the RTT150
  58. GRB 050408: steepening of the optical decay
  59. GRB 050408: Optical afterglow confirmed
  60. GRB 050408: opitcal observation
  61. GRB 050408, optical observations
  62. GRB 050408 optical candidate
  63. GRB 050408: Swift XRT Position
  64. GRB 050408: ROTSE-III Optical Limits
  65. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  66. GRB050408: MASTER optical observations
  67. GRB050401: Radio Detection
  68. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  69. GRB 050406: Magellan optical observations
  70. GRB 050406: early Swift XRT analysis results
  71. GRB 050406 BAT refined analysis
  72. GRB 050406: Early observations with Swift-UVOT
  73. GRB 050406: Swift XRT Position
  74. Swift-BAT detection of GRB 050406
  75. Konus-Wind observation of GRB 050401
  76. GRB050401: Radio observation at 610 MHz with GMRT
  77. GRB 050401: VLT spectroscopic redshift
  78. GRB 050401 Optical Observations
  79. GRB 050401 BAT refined analysis
  80. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  81. GRB050401: TNG R-band observation
  82. GRB 050402A: IR Analysis
  83. GRB 050402A: IR Observations
  84. GRB 050402: Early observations with Swift-UVOT
  85. Swift Trigger 113225: P60 Observations
  86. GRB 050401: Optical afterglow confirmed
  87. GRB 050401: Optical afterglow candidate
  88. Swift-BAT detection of GRB 050401
  89. GRB 050401: Prompt XRT position
  90. Retraction of three Swift GRB triggers
  91. GRB050331: No Afterglow Detected
  92. Swift-BAT detection of GRB 050331b
  93. GRB 050331: Swift UVOT Source
  94. Swift-BAT detection of GRB 050331
  95. GRB 050331: Swift XRT Position
  96. GRB050319: radio observation
  97. Konus-Wind observation of GRB 050326
  98. GRB 050326: Early observations with Swift-UVOT
  99. GRB 050326 XMM-Newton observation
  100. GRB 050326 : Planned XMM-Newton observation

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