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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"

19386 results found.

  1. GRB 050820: Swift detection of a GRB
  2. GRB050819: Swift-BAT detection of a weak burst
  3. GRB 050817: Optical observations
  4. GRB050817: Negative Optical Observations
  5. GRB 050814: continued fading
  6. GRB 050815: ROTSE-III Optical Limits
  7. GRB050815: Swift-BAT detection of a burst
  8. GRB050814: Fading red source
  9. GRB050814: P60 Optical Afterglow Candidate
  10. GRB 050813: Non-fading of afterglow candidate
  11. GRB 050814: XRT refined analysis
  12. GRB050814: SWIFT/UVOT observation
  13. GRB050814: Refined analysis of the Swift-BAT burst
  14. GRB 050814: Swift XRT Afterglow Localization
  15. GRB 050814: Swift detection of a burst
  16. GRB 050813: Magellan detection of a high redshift galaxy cluster
  17. GRB050813, SDSS pre-burst observations
  18. GRB050813: SWIFT/UVOT observation
  19. GRB 050813: Swift XRT afterglow localization
  20. RBO GRB 050714A and GRB 050716 observations
  21. GRB 050813: Possible Short Swift-BAT GRB
  22. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  23. Detection of an intermediate burst from SGR 1806-20 on August 8
  24. GRB 050730: WSRT Radio Observations
  25. GRB 050807: ROTSE-III Optical Limits
  26. GRB050805b: CrAO optical limit
  27. GRB050803, optical observations
  28. Retraction of Swift Trigger 149131 (GRB 050805B)
  29. GRB 050805b: OHP optical limits
  30. GRB 050805b: TAROT optical limits
  31. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  32. GRB050802: TNG optical observations
  33. GRB050803: Radio Observation
  34. GRB 050803: RTT150 optical observations
  35. GRB050801: Radio Observation
  36. GRB050730: Radio Detection
  37. GRB 050803: Keck Observations
  38. GRB 050803: Swift-BAT refined analysis
  39. GRB 050802.422: Fading of the afterglow and detection of the host
  40. GRB 050803: TAROT optical limits
  41. GRB050802 radio non-detection
  42. GRB 050730: OHP optical observations
  43. GRB 050802: Swift-BAT refined analysis
  44. GRB050801: Optical photometry and decay index
  45. GRB 050802: Swift Gamma-ray Burst
  46. GCN 050801: early Swift XRT analysis results
  47. GRB 050730: early TAROT optical observations
  48. GRB 050726: PROMPT Rc Observations
  49. GRB 050730, spectra and optical photometry
  50. GRB 050730 XMM-Newton observation
  51. GRB050730: Swift-BAT detection of a weak burst
  52. GRB 050709: PROMPT Rc Observations
  53. GRB 050724: WHT optical observations
  54. GRB050713: analysis of the XMM-Newton observation
  55. GRB050709: Second Epoch Chandra Observation
  56. GRB 050724: Optical Variability in Nearby Galaxy
  57. GRB 050724: J-band observations
  58. GRB 050724: GMOS Imaging and Spectroscopy
  59. RXTE ASM Detection of GRB050724
  60. GRB050724: Radio Observation
  61. GRB 050724: Swift/UVOT Upper Limit
  62. GRB 050724: possible host galaxy in DSS
  63. GRB 050721A: Swift-BAT refined analysis
  64. Correction to GCN Circ 3474 on GRB050525A
  65. GRB050721A: optical decay
  66. GRB 050721: optical afterglow confirmed
  67. GRB050721A: Swift-BAT detection of a weak burst
  68. GRB 050717: PROMPT RcIc Observations
  69. GRB050714b: Radio Observation
  70. GRB050712: Radio Observations
  71. GRB050713a: Radio Observation
  72. GRB 050712, Tautenburg optical afterglow observations
  73. Swift-BAT detection of a possible GRB
  74. GRB 050714B: VLT R-band observations
  75. GRB 050717: Additional LCO observations
  76. GRB050717
  77. GRB 050716; J-band observations
  78. Konus-Wind observation of GRB 050717
  79. GRB 050717: LCO near-IR observations
  80. Swift/UVOT Observations of GRB 050717
  81. GRB 050717: Swift-BAT refined analysis
  82. GRB050717: Swift XRT position
  83. Swift detection of GRB 050717
  84. Swift UVOT Observations of GRB 050716
  85. GRB 050716: Lulin B and R band optical observations
  86. GRB050716, optical observation
  87. GRB050716: Faulkes North Telescope observation
  88. Konus-Wind observation of GRB 050713A
  89. GRB 050714B: refined XRT analysis
  90. GRB 050713b: RTT150 optical observations
  91. GRB 050714B: optical afterglow
  92. GRB 050714, R-band candidate
  93. GRB 050714, optical observations
  94. GRB 050714A: ROTSE-III Optical Limits
  95. GRB 050713A: RAPTOR detection of early optical emission
  96. GRB050713B :Swift/UVOT observations
  97. GRB050712: TNG R-band observations
  98. GRB 050713A: Swift/UVOT observation
  99. GRB050712: Swift UVOT Observation of Afterglow Emission
  100. GRB 050713A : Lulin R-band observation

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