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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"

17641 results found.

  1. GRB 050412: IR Observations
  2. GRB050408: Radio Observations
  3. GRB 050408: Optical limit
  4. GRB050410: P60 Observations
  5. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  6. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  7. GRB050410: Radio Observations
  8. GRB 050408: Swift XRT measurement of possible jet break
  9. GRB050410: MASTER optical observations
  10. GRB 050410: Early observations with Swift-UVOT
  11. GRB 050408: Retraction of Proposed Host Galaxy
  12. GRB 050408: Inconsistency of host galaxy identification
  13. GRB 050408: Subaru Observations
  14. GRB 050408: WIDGET simultaneous optical observations
  15. GRB 050408: Properties of the Host Galaxy
  16. GRB 050408: Mercator Optical Observations
  17. GRB050408: Radio Observations
  18. GRB 050408: Swift XRT analysis
  19. GRB050408: REM NIR and Optical observation
  20. GRB 050408,optical observation
  21. GRB 050408: steepening of the optical decay
  22. GRB 050408: Optical afterglow confirmed
  23. GRB 050408: opitcal observation
  24. GRB 050408, optical observations
  25. GRB 050408: Swift XRT Position
  26. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  27. GRB050408: MASTER optical observations
  28. GRB050401: Radio Detection
  29. GRB 050406 BAT refined analysis
  30. GRB 050406: Early observations with Swift-UVOT
  31. Swift-BAT detection of GRB 050406
  32. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  33. GRB050401: TNG R-band observation
  34. GRB 050402: Early observations with Swift-UVOT
  35. Swift Trigger 113225: P60 Observations
  36. GRB 050401: Optical afterglow confirmed
  37. GRB050331: No Afterglow Detected
  38. GRB 050331: Swift UVOT Source
  39. GRB 050326: Early observations with Swift-UVOT
  40. GRB 050326 XMM-Newton observation
  41. GRB 050326: Swift XRT Position
  42. GRB050326: delayed XRT observation
  43. GRB050319, color indices
  44. GRB050319: optical observation, March 20-22
  45. GRB050319: RTT150 Optical Observations
  46. GRB050319: VLA Observations
  47. GRB050319: radio observation
  48. GRB 050319: Swift-UVOT detection of the afterglow
  49. GRB 050315: Variability Analysis of Swift BAT Time History
  50. GRB050319: Radio Observations
  51. GRB 050319: NIR afterglow candidate
  52. GRB 050319:Near IR afterglow
  53. GRB 050319: Swift-BAT refined analysis
  54. GRB050319,optical observation
  55. GRB 050318: Swift/UVOT detection of afterglow emission
  56. RXTE Observations of GRB050318
  57. GRB050223: analysis of the XMM-Newton observation
  58. GRB050316: MASTER before, simultanious and follow up optical
  59. GRB 050306: ROTSE-III early limits
  60. GRB050316: MASTER optical observations
  61. GRB 050315 I-band observations
  62. GRB050315: Radio afterglow
  63. GRB 050315: Early Observations with Swift/UVOT
  64. GRB 050306: Radio Observations
  65. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  66. GRB 050306: optical afterglow
  67. Swift-BAT trigger 107873: No Swift XRT counterpart
  68. GRB 050306: Confirmation of X-ray afterglow
  69. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  70. Swift 107873: P60 Optical Observations
  71. GRB 050306: R-band observations
  72. GRB 050306: REM optical-infrared observations
  73. GRB 050306: Possible X-ray Afterglow Position from the Swift
  74. GRB 050306: TAROT optical observations
  75. GRB 050306,optical observation
  76. GRB050215B: Late-Time Swift UVOT Observations
  77. PROMPT VRcIc Observations of GRB 050223
  78. XMM-Newton Images of GRB 050223
  79. GRB 050219b: candidate NIR afterglow
  80. GRB050223 XMM-Newton observation
  81. INTEGRAL detection of GRB 050223
  82. GRB050223: ROTSE-III Optical Observations
  83. GRB 050223: Swift XRT Position
  84. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  85. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  86. GRB 050219a: Optical observations from LCO
  87. GRB 050219b: Optical and near-IR observations from LCO
  88. GRB 050215b: XRT confirmation of IR afterglow candidate
  89. GRB050215b: P60 Optical Observations
  90. GRB 050215b: Swift XRT Source Variability
  91. GRB 050215b, BOOTES-2 simultaneous optical observations
  92. GRB050215B: ROTSE-III optical observations
  93. GRB050215A: ROTSE-III Optical Observations
  94. GRB050209: TAROT optical observations
  95. GRB050209: REM optical observations
  96. GRB 050209 I-band observation
  97. GRB 050209 Optical observations
  98. GRB050209: P60 Optical Observations
  99. GRB 050128: Radio observations
  100. Further analysis of the short Swift-BAT GRB 050202

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