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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"

42203 results found.

  1. GRB 050412: early Swift XRT analysis results
  2. GRB 050412 : XingLong optical observation
  3. GRB 050412: Swift-BAT refined analysis
  4. GRB 050412: ANU 2.3m observations
  5. GRB 050412: Early Optical/Ultraviolet Observations with
  6. GRB 050412: UVOT transient not in XRT error circle
  7. GRB 050408: SDSS Field Calibration
  8. GRB 050412: Optical limit
  9. GRB 050412: LCO Optical Observations
  10. GRB 050412: Optical observations
  11. GRB050412: P60 Observations
  12. GRB 050412: Swift XRT Position
  13. GRB050412: optical limit before and during GRB
  14. GRB 050412: LCO optical observations
  15. GRB050412: ROTSE-III Optical Limits
  16. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  17. GRB 050412: IR and Optical observations
  18. GRB 050412: IR Observations
  19. GRB050408: Radio Observations
  20. GRB 050401: Optical limit
  21. GRB 050408: Optical limit
  22. GRB050410: P60 Observations
  23. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  24. GRB 050410, optical observations
  25. GRB 050408: PROMPT VRcIc Observations
  26. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  27. GRB 050410 R band Optical Observations
  28. GRB 050410, optical observations
  29. GRB050410: Radio Observations
  30. GRB 050408: Swift XRT measurement of possible jet break
  31. GRB050410: MASTER optical observations
  32. GRB 050410: Early observations with Swift-UVOT
  33. Swift-BAT detection of GRB 050410
  34. GRB 050410: Swift XRT Position
  35. GRB 050408: Inconsistency of host galaxy identification
  36. GRB 050408: Subaru Observations
  37. GRB 050408: WIDGET simultaneous optical observations
  38. GRB 050408: SOAR UBVRc Observations
  39. GRB 050408: Properties of the Host Galaxy
  40. GRB 050408: Mercator Optical Observations
  41. GRB050408: Radio Observations
  42. GRB 050408: Swift XRT analysis
  43. GRB 050408, SMARTS optical/IR afterglow observations
  44. GRB 050408: Optical limit at 20 min after the burst
  45. GRB 050408, optical observations
  46. GRB050408: REM NIR and Optical observation
  47. GRB 050408: Moderate-resolution Gemini Spectroscopy
  48. GRB 050408,optical observation
  49. GRB 050408 Optical Observations
  50. GRB 050408: Emission and absorption redshift
  51. GRB 050408: Mercator Optical Observations
  52. GRB 050408: Magellan astrometry and photometry
  53. GRB 050408: First Optical observations with TFOSC at the RTT150
  54. GRB 050408: steepening of the optical decay
  55. GRB 050408: Optical afterglow confirmed
  56. GRB 050408: opitcal observation
  57. GRB 050408, optical observations
  58. GRB 050408 optical candidate
  59. GRB 050408: Swift XRT Position
  60. GRB 050408: ROTSE-III Optical Limits
  61. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  62. GRB050408: MASTER optical observations
  63. GRB050401: Radio Detection
  64. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  65. GRB 050406: Magellan optical observations
  66. GRB 050406: early Swift XRT analysis results
  67. GRB 050406 BAT refined analysis
  68. GRB 050406: Early observations with Swift-UVOT
  69. GRB 050406: Swift XRT Position
  70. Swift-BAT detection of GRB 050406
  71. Konus-Wind observation of GRB 050401
  72. GRB050401: Radio observation at 610 MHz with GMRT
  73. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  74. GRB 050401: VLT spectroscopic redshift
  75. GRB 050401 Optical Observations
  76. GRB050401: Maidanak optical observation
  77. GRB 050401 BAT refined analysis
  78. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  79. GRB050401: TNG R-band observation
  80. GRB 050402A: IR Observations
  81. GRB 050402: Early observations with Swift-UVOT
  82. Swift Trigger 113225: P60 Observations
  83. GRB050401: ROTSE-III Detection of Prompt Optical Counterpart
  84. GRB 050401: Optical afterglow confirmed
  85. GRB 050401: Optical afterglow candidate
  86. Swift-BAT detection of GRB 050401
  87. GRB 050401: Prompt XRT position
  88. GRB050331: No Afterglow Detected
  89. GRB 050331: Swift UVOT Source
  90. Swift-BAT detection of GRB 050331
  91. GRB 050331: Swift XRT Position
  92. GRB050319: radio observation
  93. Konus-Wind observation of GRB 050326
  94. GRB050326: optical limit
  95. GRB 050326: Early observations with Swift-UVOT
  96. GRB 050326 XMM-Newton observation
  97. GRB 050326 : Planned XMM-Newton observation
  98. GRB 050326: Swift XRT Position
  99. GRB050326: optical limit 33min before GRB
  100. GRB 050326 BAT refined analysis

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