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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"

19543 results found.

  1. GRB050412: P60 Observations
  2. GRB 050412: IR and Optical observations
  3. GRB 050412: IR Observations
  4. GRB050408: Radio Observations
  5. GRB 050408: Optical limit
  6. GRB050410: P60 Observations
  7. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  8. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  9. GRB050410: Radio Observations
  10. GRB 050408: Swift XRT measurement of possible jet break
  11. GRB050410: MASTER optical observations
  12. GRB 050410: Early observations with Swift-UVOT
  13. GRB 050408: Retraction of Proposed Host Galaxy
  14. GRB 050408: Inconsistency of host galaxy identification
  15. GRB 050408: Subaru Observations
  16. GRB 050408: WIDGET simultaneous optical observations
  17. GRB 050408: Properties of the Host Galaxy
  18. GRB 050408: Mercator Optical Observations
  19. GRB050408: Radio Observations
  20. GRB 050408: Swift XRT analysis
  21. GRB050408: REM NIR and Optical observation
  22. GRB 050408,optical observation
  23. GRB 050408: steepening of the optical decay
  24. GRB 050408: Optical afterglow confirmed
  25. GRB 050408: opitcal observation
  26. GRB 050408, optical observations
  27. GRB 050408: Swift XRT Position
  28. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  29. GRB050408: MASTER optical observations
  30. GRB050401: Radio Detection
  31. GRB 050406 BAT refined analysis
  32. GRB 050406: Early observations with Swift-UVOT
  33. Swift-BAT detection of GRB 050406
  34. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  35. GRB050401: TNG R-band observation
  36. GRB 050402: Early observations with Swift-UVOT
  37. Swift Trigger 113225: P60 Observations
  38. GRB 050401: Optical afterglow confirmed
  39. GRB050331: No Afterglow Detected
  40. GRB 050331: Swift UVOT Source
  41. GRB 050326: Early observations with Swift-UVOT
  42. GRB 050326 XMM-Newton observation
  43. GRB 050326: Swift XRT Position
  44. GRB050326: delayed XRT observation
  45. GRB050319, color indices
  46. GRB050319: optical observation, March 20-22
  47. GRB050319: RTT150 Optical Observations
  48. GRB050319: VLA Observations
  49. GRB050319: radio observation
  50. GRB 050319: Swift-UVOT detection of the afterglow
  51. GRB 050315: Variability Analysis of Swift BAT Time History
  52. GRB050319: Radio Observations
  53. GRB 050319: NIR afterglow candidate
  54. GRB 050319:Near IR afterglow
  55. GRB 050319: Swift-BAT refined analysis
  56. GRB050319,optical observation
  57. GRB 050318: Swift/UVOT detection of afterglow emission
  58. RXTE Observations of GRB050318
  59. GRB050223: analysis of the XMM-Newton observation
  60. GRB050316: MASTER before, simultanious and follow up optical
  61. GRB 050306: ROTSE-III early limits
  62. GRB050316: MASTER optical observations
  63. GRB 050315 I-band observations
  64. GRB050315: Radio afterglow
  65. GRB 050315: Early Observations with Swift/UVOT
  66. GRB 050306: Radio Observations
  67. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  68. GRB 050306: optical afterglow
  69. Swift-BAT trigger 107873: No Swift XRT counterpart
  70. GRB 050306: Confirmation of X-ray afterglow
  71. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  72. Swift 107873: P60 Optical Observations
  73. GRB 050306: R-band observations
  74. GRB 050306: REM optical-infrared observations
  75. GRB 050306: Possible X-ray Afterglow Position from the Swift
  76. GRB 050306: TAROT optical observations
  77. GRB 050306,optical observation
  78. GRB050215B: Late-Time Swift UVOT Observations
  79. PROMPT VRcIc Observations of GRB 050223
  80. XMM-Newton Images of GRB 050223
  81. GRB 050219b: candidate NIR afterglow
  82. GRB050223 XMM-Newton observation
  83. INTEGRAL detection of GRB 050223
  84. GRB050223: ROTSE-III Optical Observations
  85. GRB 050223: Swift XRT Position
  86. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  87. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  88. GRB 050219a: Optical observations from LCO
  89. GRB 050219b: Optical and near-IR observations from LCO
  90. GRB 050215b: XRT confirmation of IR afterglow candidate
  91. GRB050215b: P60 Optical Observations
  92. GRB 050215b: Swift XRT Source Variability
  93. GRB 050215b, BOOTES-2 simultaneous optical observations
  94. GRB050215B: ROTSE-III optical observations
  95. GRB050215A: ROTSE-III Optical Observations
  96. GRB050209: TAROT optical observations
  97. GRB050209: REM optical observations
  98. GRB 050209 I-band observation
  99. GRB 050209 Optical observations
  100. GRB050209: P60 Optical Observations

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