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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"

22095 results found.

  1. GRB 050408: ROTSE-III Optical Limits
  2. GRB050408: MASTER optical observations
  3. GRB050401: Radio Detection
  4. GRB 050406: Magellan optical observations
  5. GRB 050406 BAT refined analysis
  6. GRB 050406: Early observations with Swift-UVOT
  7. Swift-BAT detection of GRB 050406
  8. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  9. GRB 050401 BAT refined analysis
  10. GRB050401: TNG R-band observation
  11. GRB 050402: Early observations with Swift-UVOT
  12. Swift Trigger 113225: P60 Observations
  13. GRB 050401: Optical afterglow confirmed
  14. GRB050331: No Afterglow Detected
  15. GRB 050331: Swift UVOT Source
  16. Konus-Wind observation of GRB 050326
  17. GRB 050326: Early observations with Swift-UVOT
  18. GRB 050326 XMM-Newton observation
  19. GRB 050326: Swift XRT Position
  20. GRB050326: optical limit 33min before GRB
  21. GRB 050326 BAT refined analysis
  22. GRB050326: delayed XRT observation
  23. GRB050319, optical observations
  24. GRB050319: optical observation, March 20-22
  25. GRB050319: RTT150 Optical Observations
  26. GRB050319: VLA Observations
  27. GRB050319: radio observation
  28. GRB 050319: Swift-UVOT detection of the afterglow
  29. GRB050319: Radio Observations
  30. GRB 050319: NIR afterglow candidate
  31. GRB 050319:Near IR afterglow
  32. GRB 050318: SWIFT-UVOT refined analysis
  33. GRB050319,optical observation
  34. GRB 050318: Swift/UVOT detection of afterglow emission
  35. RXTE Observations of GRB050318
  36. Swift-BAT detection of GRB 050318
  37. GRB050223: analysis of the XMM-Newton observation
  38. GRB050316: MASTER before, simultanious and follow up optical
  39. GRB 050306: ROTSE-III early limits
  40. GRB050316: MASTER optical observations
  41. GRB 050315 I-band observations
  42. GRB050315: Radio afterglow
  43. Non-detection of GRB050315 in ATCA Radio Observations
  44. GRB 050315: Early Observations with Swift/UVOT
  45. Swift-BAT detection of GRB 050315
  46. GRB 050306: Radio Observations
  47. GRB 050306: optical afterglow
  48. Swift-BAT trigger 107873: No Swift XRT counterpart
  49. GRB 050306: Confirmation of X-ray afterglow
  50. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  51. GRB 050309 : Lulin R-band observation
  52. Swift 107873: P60 Optical Observations
  53. GRB 050306: R-band observations
  54. GRB 050306: REM optical-infrared observations
  55. GRB 050306: Possible X-ray Afterglow Position from the Swift
  56. GRB 050306: TAROT optical observations
  57. GRB 050306,optical observation
  58. GRB 050306: Swift-BAT detection of a long burst
  59. Ongoing activity of SGR 1806-20 after the giant flare
  60. GRB050215B: Late-Time Swift UVOT Observations
  61. PROMPT VRcIc Observations of GRB 050223
  62. XRF/GRB 050215B: Radio Observations
  63. XMM-Newton Images of GRB 050223
  64. GRB 050219b: candidate NIR afterglow
  65. GRB050223 XMM-Newton observation
  66. INTEGRAL detection of GRB 050223
  67. GRB050223: ROTSE-III Optical Observations
  68. GRB 050223: Swift XRT Position
  69. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  70. GRB050219b: CORRECTION to time of UVOT observations
  71. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  72. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  73. GRB 050219a: Optical observations from LCO
  74. GRB 050219b: Optical and near-IR observations from LCO
  75. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  76. GRB 050219b: Refined XRT position
  77. GRB 050219b: CORRECTION: Swift XRT Position
  78. GRB 050219b: Swift XRT Position
  79. GRB 050219a, optical observations
  80. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  81. GRB 050215B: Radio Observations
  82. GRB 050215b: XRT confirmation of IR afterglow candidate
  83. GRB050215b: P60 Optical Observations
  84. GRB 050215b: Swift XRT Source Variability
  85. GRB 050215b : Lulin follow-up observation
  86. GRB 050215b, BOOTES-2 simultaneous optical observations
  87. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  88. GRB 050215b, BOOTES-1B optical limit
  89. GRB050215B: ROTSE-III optical observations
  90. GRB050215A: ROTSE-III Optical Observations
  91. GRB050209: TAROT optical observations
  92. GRB 050209(=U11568): Duration and spectrum
  93. short/hard GRB 050202, optical observations
  94. GRB050209: REM optical observations
  95. GRB 050209 I-band observation
  96. GRB 050209 Optical observations
  97. GRB050209: P60 Optical Observations
  98. GRB 050128: Radio observations
  99. GRB 050129: Optical observations
  100. GRB 050202: Short burst detected by Swift-BAT

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