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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"

34021 results found.

  1. GRB 050408: RTT150 optical observations
  2. GRB 050412: PROMPT VRcIc Observations
  3. GRB 050408: Kuiper 1.5m observations
  4. GRB 050412: optical limit
  5. GRB 050412: optical observations
  6. GRB 050408: refined XRT analysis, no jet break seen yet
  7. GRB 050412: early Swift XRT analysis results
  8. GRB 050412 : XingLong optical observation
  9. GRB 050412: Swift-BAT refined analysis
  10. GRB 050412: ANU 2.3m observations
  11. GRB 050412: Early Optical/Ultraviolet Observations with
  12. GRB 050412: retraction of UVOT transient report
  13. GRB 050412: UVOT transient not in XRT error circle
  14. GRB 050408: SDSS Field Calibration
  15. GRB 050412: Optical limit
  16. GRB 050412: LCO Optical Observations
  17. GRB 050412: Optical observations
  18. GRB050412: P60 Observations
  19. GRB 050412: Swift XRT Position
  20. GRB050412: optical limit before and during GRB
  21. GRB 050412: LCO optical observations
  22. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  23. GRB 050412: IR and Optical observations
  24. GRB 050412: IR Observations
  25. GRB050408: Radio Observations
  26. GRB 050401: Optical limit
  27. GRB 050408: Optical limit
  28. GRB050410: P60 Observations
  29. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  30. GRB 050410, optical observations
  31. GRB 050408: PROMPT VRcIc Observations
  32. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  33. GRB 050410 R band Optical Observations
  34. GRB050410 : Null detection report
  35. GRB 050410, optical observations
  36. GRB050410: Radio Observations
  37. GRB 050408: Swift XRT measurement of possible jet break
  38. GRB050410: MASTER optical observations
  39. GRB 050410: Early observations with Swift-UVOT
  40. Swift-BAT detection of GRB 050410
  41. GRB 050410: Swift XRT Position
  42. GRB 050408: Retraction of Proposed Host Galaxy
  43. GRB 050408: Inconsistency of host galaxy identification
  44. GRB 050408: Subaru Observations
  45. GRB 050408: WIDGET simultaneous optical observations
  46. GRB 050408: SOAR UBVRc Observations
  47. GRB 050408: Properties of the Host Galaxy
  48. GRB 050408: Mercator Optical Observations
  49. GRB050408: Radio Observations
  50. GRB 050408: Swift XRT analysis
  51. GRB 050408, SMARTS optical/IR afterglow observations
  52. GRB 050408: Optical limit at 20 min after the burst
  53. GRB 050408, optical observations
  54. GRB 050408: Moderate-resolution Gemini Spectroscopy
  55. GRB 050408,optical observation
  56. GRB 050408 Optical Observations
  57. GRB 050408: Emission and absorption redshift
  58. GRB 050408: Mercator Optical Observations
  59. GRB 050408: Magellan astrometry and photometry
  60. GRB 050408: First Optical observations with TFOSC at the RTT150
  61. GRB 050408: steepening of the optical decay
  62. GRB 050408: Optical afterglow confirmed
  63. GRB 050408: opitcal observation
  64. GRB 050408, optical observations
  65. GRB 050408 optical candidate
  66. GRB 050408: Swift XRT Position
  67. GRB 050408: ROTSE-III Optical Limits
  68. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  69. GRB050408: MASTER optical observations
  70. GRB050401: Radio Detection
  71. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  72. GRB 050406: Magellan optical observations
  73. GRB 050406: early Swift XRT analysis results
  74. GRB 050406 BAT refined analysis
  75. GRB 050406: Early observations with Swift-UVOT
  76. GRB 050406: Swift XRT Position
  77. Swift-BAT detection of GRB 050406
  78. Konus-Wind observation of GRB 050401
  79. GRB050401: Radio observation at 610 MHz with GMRT
  80. GRB 050401: VLT spectroscopic redshift
  81. GRB 050401 Optical Observations
  82. GRB 050401 BAT refined analysis
  83. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  84. GRB050401: TNG R-band observation
  85. GRB 050402A: IR Analysis
  86. GRB 050402A: IR Observations
  87. GRB 050402: Early observations with Swift-UVOT
  88. Swift Trigger 113225: P60 Observations
  89. GRB 050401: Optical afterglow confirmed
  90. GRB 050401: Optical afterglow candidate
  91. Swift-BAT detection of GRB 050401
  92. GRB 050401: Prompt XRT position
  93. Retraction of three Swift GRB triggers
  94. GRB050331: No Afterglow Detected
  95. Swift-BAT detection of GRB 050331b
  96. GRB 050331: Swift UVOT Source
  97. Swift-BAT detection of GRB 050331
  98. GRB 050331: Swift XRT Position
  99. GRB050319: radio observation
  100. Konus-Wind observation of GRB 050326

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