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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"

35955 results found.

  1. GRB 050408, optical observations
  2. GRB 050408: Moderate-resolution Gemini Spectroscopy
  3. GRB 050408,optical observation
  4. GRB 050408 Optical Observations
  5. GRB 050408: Emission and absorption redshift
  6. GRB 050408: Mercator Optical Observations
  7. GRB 050408: Magellan astrometry and photometry
  8. GRB 050408: First Optical observations with TFOSC at the RTT150
  9. GRB 050408: steepening of the optical decay
  10. GRB 050408: Optical afterglow confirmed
  11. GRB 050408: opitcal observation
  12. GRB 050408, optical observations
  13. GRB 050408 optical candidate
  14. GRB 050408: Swift XRT Position
  15. GRB 050408: ROTSE-III Optical Limits
  16. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  17. GRB050408: MASTER optical observations
  18. GRB050401: Radio Detection
  19. Swift-UVOT Optical Counterpart Candidate to XRF 050406
  20. GRB 050406: Magellan optical observations
  21. GRB 050406: early Swift XRT analysis results
  22. GRB 050406 BAT refined analysis
  23. GRB 050406: Early observations with Swift-UVOT
  24. GRB 050406: Swift XRT Position
  25. Swift-BAT detection of GRB 050406
  26. Konus-Wind observation of GRB 050401
  27. GRB050401: Radio observation at 610 MHz with GMRT
  28. GRB 050401: VLT spectroscopic redshift
  29. GRB 050401 Optical Observations
  30. GRB 050401 BAT refined analysis
  31. Very questionable identity of Swift-BAT GRB050402 (Trig=113225)
  32. GRB050401: TNG R-band observation
  33. GRB 050402A: IR Analysis
  34. GRB 050402A: IR Observations
  35. GRB 050402: Early observations with Swift-UVOT
  36. Swift Trigger 113225: P60 Observations
  37. GRB 050401: Optical afterglow confirmed
  38. GRB 050401: Optical afterglow candidate
  39. Swift-BAT detection of GRB 050401
  40. GRB 050401: Prompt XRT position
  41. Retraction of three Swift GRB triggers
  42. GRB050331: No Afterglow Detected
  43. Swift-BAT detection of GRB 050331b
  44. GRB 050331: Swift UVOT Source
  45. Swift-BAT detection of GRB 050331
  46. GRB 050331: Swift XRT Position
  47. GRB050319: radio observation
  48. Konus-Wind observation of GRB 050326
  49. GRB 050326: Early observations with Swift-UVOT
  50. GRB 050326 XMM-Newton observation
  51. GRB 050326 : Planned XMM-Newton observation
  52. GRB 050326: Swift XRT Position
  53. GRB050326: optical limit 33min before GRB
  54. GRB 050326 BAT refined analysis
  55. GRB050326: delayed XRT observation
  56. Swift-BAT detection of a bright GRB 050326
  57. GRB050319, color indices
  58. GRB050319: RTT150 Optical Observations
  59. Swift-BAT trigger 112060 is not a real GRB
  60. GRB 050319: Absorption redshift from the Nordic Optical Telescope
  61. GRB 050319: ROTSE-III Refined Analysis
  62. GRB 050318: Swift-BAT refined analysis
  63. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  64. GRB050319: VLA Observations
  65. GRB 050319 R band observations
  66. GRB 050319: Swift-UVOT detection of the afterglow
  67. GRB 050315: Variability Analysis of Swift BAT Time History
  68. GRB050319: Radio Observations
  69. GRB 050319: NIR afterglow candidate
  70. GRB 050319:Near IR afterglow
  71. GRB 050318: SWIFT-UVOT refined analysis
  72. GRB 050318: Absorption redshift from Magellan
  73. GRB 050319: Optical observation
  74. GRB 050319 : Confirmation of optical afterglow decay
  75. GRB 050319: Swift-BAT refined analysis
  76. GRB050319,optical observation
  77. Swift Detection of GRB 050319
  78. GRB 050319: Detection of Possible Optical Counterpart
  79. GRB 050318: Swift/UVOT detection of afterglow emission
  80. GRB 050318: Magellan optical afterglow identification
  81. GRB050318: Swift XRT position
  82. RXTE Observations of GRB050318
  83. Swift-BAT detection of GRB 050318
  84. GRB 050315, SMARTS optical afterglow decay
  85. GRB050316: MASTER before, simultanious and follow up optical
  86. GRB 050306: ROTSE-III early limits
  87. GRB050316: MASTER optical observations
  88. GRB 050315: Swift-BAT further refined analysis
  89. GRB 050315, SMARTS optical/IR afterglow observations
  90. GRB 050315 I-band observations
  91. GRB050315: Radio afterglow
  92. GRB 050315: Absorption redshift
  93. GRB 050315: Optical afterglow identification
  94. GRB050315: Swift-BAT Refined analysis
  95. Non-detection of GRB050315 in ATCA Radio Observations
  96. GRB 050315: Swift XRT Position
  97. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  98. GRB 050315: Early Observations with Swift/UVOT
  99. Swift-BAT detection of GRB 050315
  100. GRB 050306: Radio Observations

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