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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"

19548 results found.

  1. Swift BAT/XRT Detection of GRB 050416
  2. GRB 050408: Kuiper 1.5m observations
  3. GRB 050412: Swift-BAT refined analysis
  4. GRB 050412: Early Optical/Ultraviolet Observations with
  5. GRB 050408: SDSS Field Calibration
  6. GRB050412: P60 Observations
  7. GRB 050412: IR and Optical observations
  8. GRB 050412: IR Observations
  9. GRB050408: Radio Observations
  10. GRB 050408: Optical limit
  11. GRB050410: P60 Observations
  12. GRB 050410: Early Optical/Ultraviolet Observations with Swift/UVOT
  13. GRB 050408: Early Optical/Ultraviolet Observations with Swift/UVOT
  14. GRB050410: Radio Observations
  15. GRB 050408: Swift XRT measurement of possible jet break
  16. GRB050410: MASTER optical observations
  17. GRB 050410: Early observations with Swift-UVOT
  18. GRB 050408: Retraction of Proposed Host Galaxy
  19. GRB 050408: Inconsistency of host galaxy identification
  20. GRB 050408: Subaru Observations
  21. GRB 050408: WIDGET simultaneous optical observations
  22. GRB 050408: Properties of the Host Galaxy
  23. GRB 050408: Mercator Optical Observations
  24. GRB050408: Radio Observations
  25. GRB 050408: Swift XRT analysis
  26. GRB050408: REM NIR and Optical observation
  27. GRB 050408,optical observation
  28. GRB 050408: steepening of the optical decay
  29. GRB 050408: Optical afterglow confirmed
  30. GRB 050408: opitcal observation
  31. GRB 050408, optical observations
  32. GRB 050408: Swift XRT Position
  33. GRB 050408 (=H3711): A Long X-Ray-Rich GRB Detected by HETE
  34. GRB050408: MASTER optical observations
  35. GRB050401: Radio Detection
  36. GRB 050406 BAT refined analysis
  37. GRB 050406: Early observations with Swift-UVOT
  38. Swift-BAT detection of GRB 050406
  39. GRB050401, radio observation at 4.8 GHz and 8.64 GHz
  40. GRB050401: TNG R-band observation
  41. GRB 050402: Early observations with Swift-UVOT
  42. Swift Trigger 113225: P60 Observations
  43. GRB 050401: Optical afterglow confirmed
  44. GRB050331: No Afterglow Detected
  45. GRB 050331: Swift UVOT Source
  46. GRB 050326: Early observations with Swift-UVOT
  47. GRB 050326 XMM-Newton observation
  48. GRB 050326: Swift XRT Position
  49. GRB050326: delayed XRT observation
  50. GRB050319, color indices
  51. GRB050319: optical observation, March 20-22
  52. GRB050319: RTT150 Optical Observations
  53. GRB050319: VLA Observations
  54. GRB050319: radio observation
  55. GRB 050319: Swift-UVOT detection of the afterglow
  56. GRB 050315: Variability Analysis of Swift BAT Time History
  57. GRB050319: Radio Observations
  58. GRB 050319: NIR afterglow candidate
  59. GRB 050319:Near IR afterglow
  60. GRB 050319: Swift-BAT refined analysis
  61. GRB050319,optical observation
  62. GRB 050318: Swift/UVOT detection of afterglow emission
  63. RXTE Observations of GRB050318
  64. GRB050223: analysis of the XMM-Newton observation
  65. GRB050316: MASTER before, simultanious and follow up optical
  66. GRB 050306: ROTSE-III early limits
  67. GRB050316: MASTER optical observations
  68. GRB 050315 I-band observations
  69. GRB050315: Radio afterglow
  70. GRB 050315: Early Observations with Swift/UVOT
  71. GRB 050306: Radio Observations
  72. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  73. GRB 050306: optical afterglow
  74. Swift-BAT trigger 107873: No Swift XRT counterpart
  75. GRB 050306: Confirmation of X-ray afterglow
  76. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  77. Swift 107873: P60 Optical Observations
  78. GRB 050306: R-band observations
  79. GRB 050306: REM optical-infrared observations
  80. GRB 050306: Possible X-ray Afterglow Position from the Swift
  81. GRB 050306: TAROT optical observations
  82. GRB 050306,optical observation
  83. GRB050215B: Late-Time Swift UVOT Observations
  84. PROMPT VRcIc Observations of GRB 050223
  85. XMM-Newton Images of GRB 050223
  86. GRB 050219b: candidate NIR afterglow
  87. GRB050223 XMM-Newton observation
  88. INTEGRAL detection of GRB 050223
  89. GRB050223: ROTSE-III Optical Observations
  90. GRB 050223: Swift XRT Position
  91. HETE-2 Observations of GRB 050215b (=U11570): A Likely X-Ray Flash
  92. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  93. GRB 050219a: Optical observations from LCO
  94. GRB 050219b: Optical and near-IR observations from LCO
  95. GRB 050215b: XRT confirmation of IR afterglow candidate
  96. GRB050215b: P60 Optical Observations
  97. GRB 050215b: Swift XRT Source Variability
  98. GRB 050215b, BOOTES-2 simultaneous optical observations
  99. GRB050215B: ROTSE-III optical observations
  100. GRB050215A: ROTSE-III Optical Observations

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