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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"

20392 results found.

  1. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  2. GRB 050410 R band Optical Observations
  3. GRB050410: Radio Observations
  4. GRB050410: MASTER optical observations
  5. GRB 050410: Early observations with Swift-UVOT
  6. GRB 050408: Inconsistency of host galaxy identification
  7. GRB 050408: Subaru Observations
  8. GRB 050408: WIDGET simultaneous optical observations
  9. GRB 050408: Properties of the Host Galaxy
  10. GRB050408: Radio Observations
  11. GRB050408: REM NIR and Optical observation
  12. GRB 050408,optical observation
  13. GRB 050408: Optical afterglow confirmed
  14. GRB 050408: opitcal observation
  15. GRB 050408, optical observations
  16. GRB 050408: Swift XRT Position
  17. GRB050408: MASTER optical observations
  18. GRB050401: Radio Detection
  19. GRB 050406: Early observations with Swift-UVOT
  20. Swift-BAT detection of GRB 050406
  21. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  22. GRB 050401 BAT refined analysis
  23. GRB050401: TNG R-band observation
  24. GRB 050402: Early observations with Swift-UVOT
  25. Swift Trigger 113225: P60 Observations
  26. GRB 050401: Optical afterglow confirmed
  27. GRB050331: No Afterglow Detected
  28. GRB 050331: Swift UVOT Source
  29. GRB 050326: Early observations with Swift-UVOT
  30. GRB 050326 XMM-Newton observation
  31. GRB 050326: Swift XRT Position
  32. GRB050326: delayed XRT observation
  33. GRB050319: optical observation, March 20-22
  34. GRB050319: RTT150 Optical Observations
  35. GRB050319: VLA Observations
  36. GRB050319: radio observation
  37. GRB 050319: Swift-UVOT detection of the afterglow
  38. GRB050319: Radio Observations
  39. GRB 050319: NIR afterglow candidate
  40. GRB 050319:Near IR afterglow
  41. GRB050319,optical observation
  42. GRB 050318: Swift/UVOT detection of afterglow emission
  43. RXTE Observations of GRB050318
  44. GRB050223: analysis of the XMM-Newton observation
  45. GRB050316: MASTER before, simultanious and follow up optical
  46. GRB 050306: ROTSE-III early limits
  47. GRB050316: MASTER optical observations
  48. GRB 050315 I-band observations
  49. GRB050315: Radio afterglow
  50. GRB 050315: Early Observations with Swift/UVOT
  51. GRB 050306: Radio Observations
  52. GRB 050306: optical afterglow
  53. Swift-BAT trigger 107873: No Swift XRT counterpart
  54. GRB 050306: Confirmation of X-ray afterglow
  55. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  56. Swift 107873: P60 Optical Observations
  57. GRB 050306: R-band observations
  58. GRB 050306: REM optical-infrared observations
  59. GRB 050306: Possible X-ray Afterglow Position from the Swift
  60. Swift trigger 107518: optical observation
  61. GRB 050306: TAROT optical observations
  62. GRB 050306,optical observation
  63. GRB050215B: Late-Time Swift UVOT Observations
  64. PROMPT VRcIc Observations of GRB 050223
  65. XMM-Newton Images of GRB 050223
  66. GRB 050219b: candidate NIR afterglow
  67. GRB 050223: optical observations
  68. GRB050223 XMM-Newton observation
  69. GRB050223: ROTSE-III Optical Observations
  70. GRB 050223 Swift/BAT detection of a burst
  71. GRB 050223: Swift XRT Position
  72. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  73. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  74. GRB 050219a: Optical observations from LCO
  75. GRB 050219b: Optical and near-IR observations from LCO
  76. GRB 050219b: Swift-BAT detection of a burst
  77. GRB 050219b: CORRECTION: Swift XRT Position
  78. GRB 050219b: Swift XRT Position
  79. GRB 050219a, optical observations
  80. GRB 050219: Swift-BAT detection of a burst
  81. GRB 050215b: XRT confirmation of IR afterglow candidate
  82. GRB050215b: P60 Optical Observations
  83. GRB 050215b: Swift XRT Source Variability
  84. GRB 050215b, BOOTES-2 simultaneous optical observations
  85. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  86. GRB050215A: ROTSE-III Optical Observations
  87. GRB050209: TAROT optical observations
  88. GRB050209: REM optical observations
  89. GRB 050209 I-band observation
  90. GRB 050209 Optical observations
  91. GRB050209: P60 Optical Observations
  92. GRB 050128: Radio observations
  93. Further analysis of the short Swift-BAT GRB 050202
  94. GRB 050202: Optical observations with LCO40
  95. GRB 050202: Short burst detected by Swift-BAT
  96. GRB 050128 Optical observation with REM
  97. GRB 050128: near-infrared observations with REM
  98. GRB050128,optical observations
  99. GRB050126: Updated Swift XRT Position
  100. GRB 050126: Radio Observations

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