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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"

35988 results found.

  1. GRB050412: optical limit before and during GRB
  2. GRB 050412: LCO optical observations
  3. Swift-BAT Detection of GRB 050412: A Bright, Long Burst
  4. GRB 050412: IR and Optical observations
  5. GRB 050412: IR Observations
  6. GRB050408: Radio Observations
  7. GRB 050401: Optical limit
  8. GRB 050408: Optical limit
  9. GRB050410: P60 Observations
  10. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  11. GRB 050410, optical observations
  12. GRB 050408: PROMPT VRcIc Observations
  13. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  14. GRB 050410 R band Optical Observations
  15. GRB050410 : Null detection report
  16. GRB 050410, optical observations
  17. GRB050410: Radio Observations
  18. GRB 050408: Swift XRT measurement of possible jet break
  19. GRB050410: MASTER optical observations
  20. GRB 050410: Early observations with Swift-UVOT
  21. Swift-BAT detection of GRB 050410
  22. GRB 050410: Swift XRT Position
  23. GRB 050408: Retraction of Proposed Host Galaxy
  24. GRB 050408: Inconsistency of host galaxy identification
  25. GRB 050408: Subaru Observations
  26. GRB 050408: WIDGET simultaneous optical observations
  27. GRB 050408: SOAR UBVRc Observations
  28. GRB 050408: Properties of the Host Galaxy
  29. GRB 050408: Mercator Optical Observations
  30. GRB050408: Radio Observations
  31. GRB 050408: Swift XRT analysis
  32. GRB 050408, SMARTS optical/IR afterglow observations
  33. GRB 050408: Optical limit at 20 min after the burst
  34. GRB 050408, optical observations
  35. GRB 050408: Moderate-resolution Gemini Spectroscopy
  36. GRB 050408,optical observation
  37. GRB 050408 Optical Observations
  38. GRB 050408: Emission and absorption redshift
  39. GRB 050408: Mercator Optical Observations
  40. GRB 050408: Magellan astrometry and photometry
  41. GRB 050408: First Optical observations with TFOSC at the RTT150
  42. GRB 050408: steepening of the optical decay
  43. GRB 050408: Optical afterglow confirmed
  44. GRB 050408: opitcal observation
  45. GRB 050408, optical observations
  46. GRB 050408 optical candidate
  47. GRB 050408: Swift XRT Position
  48. GRB 050408: ROTSE-III Optical Limits
  49. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  50. GRB050408: MASTER optical observations
  51. GRB050401: Radio Detection
  52. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  53. GRB 050406: Magellan optical observations
  54. GRB 050406: early Swift XRT analysis results
  55. GRB 050406 BAT refined analysis
  56. GRB 050406: Early observations with Swift-UVOT
  57. GRB 050406: Swift XRT Position
  58. Swift-BAT detection of GRB 050406
  59. Konus-Wind observation of GRB 050401
  60. GRB050401: Radio observation at 610 MHz with GMRT
  61. GRB 050401: VLT spectroscopic redshift
  62. GRB 050401 Optical Observations
  63. GRB 050401 BAT refined analysis
  64. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  65. GRB050401: TNG R-band observation
  66. GRB 050402A: IR Analysis
  67. GRB 050402A: IR Observations
  68. GRB 050402: Early observations with Swift-UVOT
  69. Swift Trigger 113225: P60 Observations
  70. GRB 050401: Optical afterglow confirmed
  71. GRB 050401: Optical afterglow candidate
  72. Swift-BAT detection of GRB 050401
  73. GRB 050401: Prompt XRT position
  74. Retraction of three Swift GRB triggers
  75. GRB050331: No Afterglow Detected
  76. Swift-BAT detection of GRB 050331b
  77. GRB 050331: Swift UVOT Source
  78. Swift-BAT detection of GRB 050331
  79. GRB 050331: Swift XRT Position
  80. GRB050319: radio observation
  81. Konus-Wind observation of GRB 050326
  82. GRB 050326: Early observations with Swift-UVOT
  83. GRB 050326 XMM-Newton observation
  84. GRB 050326 : Planned XMM-Newton observation
  85. GRB 050326: Swift XRT Position
  86. GRB050326: optical limit 33min before GRB
  87. GRB 050326 BAT refined analysis
  88. GRB050326: delayed XRT observation
  89. Swift-BAT detection of a bright GRB 050326
  90. GRB050319, color indices
  91. GRB050319: RTT150 Optical Observations
  92. Swift-BAT trigger 112060 is not a real GRB
  93. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  94. GRB 050319: ROTSE-III Refined Analysis
  95. GRB 050318: Swift-BAT refined analysis
  96. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  97. GRB050319: VLA Observations
  98. GRB 050319 R band observations
  99. GRB 050319: Swift-UVOT detection of the afterglow
  100. GRB 050315: Variability Analysis of Swift BAT Time History

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