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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"

35993 results found.

  1. GRB 050412: Optical limit
  2. GRB 050412: LCO Optical Observations
  3. GRB 050412: Optical observations
  4. GRB050412: P60 Observations
  5. GRB 050412: Swift XRT Position
  6. GRB050412: optical limit before and during GRB
  7. GRB 050412: LCO optical observations
  8. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  9. GRB 050412: IR and Optical observations
  10. GRB 050412: IR Observations
  11. GRB050408: Radio Observations
  12. GRB 050401: Optical limit
  13. GRB 050408: Optical limit
  14. GRB050410: P60 Observations
  15. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  16. GRB 050410, optical observations
  17. GRB 050408: PROMPT VRcIc Observations
  18. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  19. GRB 050410 R band Optical Observations
  20. GRB050410 : Null detection report
  21. GRB 050410, optical observations
  22. GRB050410: Radio Observations
  23. GRB 050408: Swift XRT measurement of possible jet break
  24. GRB050410: MASTER optical observations
  25. GRB 050410: Early observations with Swift-UVOT
  26. Swift-BAT detection of GRB 050410
  27. GRB 050410: Swift XRT Position
  28. GRB 050408: Retraction of Proposed Host Galaxy
  29. GRB 050408: Inconsistency of host galaxy identification
  30. GRB 050408: Subaru Observations
  31. GRB 050408: WIDGET simultaneous optical observations
  32. GRB 050408: SOAR UBVRc Observations
  33. GRB 050408: Properties of the Host Galaxy
  34. GRB 050408: Mercator Optical Observations
  35. GRB050408: Radio Observations
  36. GRB 050408: Swift XRT analysis
  37. GRB 050408, SMARTS optical/IR afterglow observations
  38. GRB 050408: Optical limit at 20 min after the burst
  39. GRB 050408, optical observations
  40. GRB 050408: Moderate-resolution Gemini Spectroscopy
  41. GRB 050408,optical observation
  42. GRB 050408 Optical Observations
  43. GRB 050408: Emission and absorption redshift
  44. GRB 050408: Mercator Optical Observations
  45. GRB 050408: Magellan astrometry and photometry
  46. GRB 050408: First Optical observations with TFOSC at the RTT150
  47. GRB 050408: steepening of the optical decay
  48. GRB 050408: Optical afterglow confirmed
  49. GRB 050408: opitcal observation
  50. GRB 050408, optical observations
  51. GRB 050408 optical candidate
  52. GRB 050408: Swift XRT Position
  53. GRB 050408: ROTSE-III Optical Limits
  54. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  55. GRB050408: MASTER optical observations
  56. GRB050401: Radio Detection
  57. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  58. GRB 050406: Magellan optical observations
  59. GRB 050406: early Swift XRT analysis results
  60. GRB 050406 BAT refined analysis
  61. GRB 050406: Early observations with Swift-UVOT
  62. GRB 050406: Swift XRT Position
  63. Swift-BAT detection of GRB 050406
  64. Konus-Wind observation of GRB 050401
  65. GRB050401: Radio observation at 610 MHz with GMRT
  66. GRB 050401: VLT spectroscopic redshift
  67. GRB 050401 Optical Observations
  68. GRB 050401 BAT refined analysis
  69. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  70. GRB050401: TNG R-band observation
  71. GRB 050402A: IR Analysis
  72. GRB 050402A: IR Observations
  73. GRB 050402: Early observations with Swift-UVOT
  74. Swift Trigger 113225: P60 Observations
  75. GRB 050401: Optical afterglow confirmed
  76. GRB 050401: Optical afterglow candidate
  77. Swift-BAT detection of GRB 050401
  78. GRB 050401: Prompt XRT position
  79. Retraction of three Swift GRB triggers
  80. GRB050331: No Afterglow Detected
  81. Swift-BAT detection of GRB 050331b
  82. GRB 050331: Swift UVOT Source
  83. Swift-BAT detection of GRB 050331
  84. GRB 050331: Swift XRT Position
  85. GRB050319: radio observation
  86. Konus-Wind observation of GRB 050326
  87. GRB 050326: Early observations with Swift-UVOT
  88. GRB 050326 XMM-Newton observation
  89. GRB 050326 : Planned XMM-Newton observation
  90. GRB 050326: Swift XRT Position
  91. GRB050326: optical limit 33min before GRB
  92. GRB 050326 BAT refined analysis
  93. GRB050326: delayed XRT observation
  94. Swift-BAT detection of a bright GRB 050326
  95. GRB050319, color indices
  96. GRB050319: RTT150 Optical Observations
  97. Swift-BAT trigger 112060 is not a real GRB
  98. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  99. GRB 050319: ROTSE-III Refined Analysis
  100. GRB 050318: Swift-BAT refined analysis

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