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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"

19498 results found.

  1. GRB050813: Maidanak I-band observations
  2. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  3. GRB050820B at FRAM
  4. Swift/UVOT UV Photometry of GRB 050820B
  5. GRB 050822: ROTSE-III Prompt Optical Limits
  6. GRB 050822: Swift detection of a long burst
  7. GRB050820a BVRcIc field photometry
  8. GRB050820B XMM-Newton observation
  9. GRB 050820B: Swift XRT position
  10. Swift/UVOT photometry of GRB050820
  11. GRB050820: refined XRT analysis
  12. GRB050819: refined XRT analysis
  13. GRB 050820: Swift detection of a GRB
  14. GRB050819: Swift-BAT detection of a weak burst
  15. GRB 050817: Optical observations
  16. GRB050817: Negative Optical Observations
  17. GRB 050814: continued fading
  18. GRB 050815: ROTSE-III Optical Limits
  19. GRB050815: Swift-BAT detection of a burst
  20. GRB050814: Fading red source
  21. GRB050814: P60 Optical Afterglow Candidate
  22. GRB 050813: Non-fading of afterglow candidate
  23. GRB 050814: XRT refined analysis
  24. GRB050814: SWIFT/UVOT observation
  25. GRB050814: Refined analysis of the Swift-BAT burst
  26. GRB 050814: Swift XRT Afterglow Localization
  27. GRB 050814: Swift detection of a burst
  28. GRB 050813: Magellan detection of a high redshift galaxy cluster
  29. GRB050813, SDSS pre-burst observations
  30. GRB050813: SWIFT/UVOT observation
  31. GRB 050813: Swift XRT afterglow localization
  32. RBO GRB 050714A and GRB 050716 observations
  33. GRB 050813: Possible Short Swift-BAT GRB
  34. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  35. Detection of an intermediate burst from SGR 1806-20 on August 8
  36. GRB 050730: WSRT Radio Observations
  37. GRB 050807: ROTSE-III Optical Limits
  38. GRB050805b: CrAO optical limit
  39. GRB050803, optical observations
  40. Retraction of Swift Trigger 149131 (GRB 050805B)
  41. GRB 050805b: OHP optical limits
  42. GRB 050805b: TAROT optical limits
  43. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  44. GRB050802: TNG optical observations
  45. GRB050803: Radio Observation
  46. GRB 050803: RTT150 optical observations
  47. GRB050801: Radio Observation
  48. GRB050730: Radio Detection
  49. GRB 050803: Keck Observations
  50. GRB 050803: Swift-BAT refined analysis
  51. GRB 050802.422: Fading of the afterglow and detection of the host
  52. GRB 050803: TAROT optical limits
  53. GRB050802 radio non-detection
  54. GRB 050730: OHP optical observations
  55. GRB 050802: Swift-BAT refined analysis
  56. GRB050801: Optical photometry and decay index
  57. GRB 050802: Swift Gamma-ray Burst
  58. GCN 050801: early Swift XRT analysis results
  59. GRB 050730: early TAROT optical observations
  60. GRB 050726: PROMPT Rc Observations
  61. GRB 050730, spectra and optical photometry
  62. GRB 050730 XMM-Newton observation
  63. GRB050730: Swift-BAT detection of a weak burst
  64. GRB 050709: PROMPT Rc Observations
  65. GRB 050724: WHT optical observations
  66. GRB050713: analysis of the XMM-Newton observation
  67. GRB050709: Second Epoch Chandra Observation
  68. GRB 050724: Optical Variability in Nearby Galaxy
  69. GRB 050724: J-band observations
  70. GRB 050724: GMOS Imaging and Spectroscopy
  71. RXTE ASM Detection of GRB050724
  72. GRB050724: Radio Observation
  73. GRB 050724: Swift/UVOT Upper Limit
  74. GRB 050724: possible host galaxy in DSS
  75. GRB 050721A: Swift-BAT refined analysis
  76. Correction to GCN Circ 3474 on GRB050525A
  77. GRB050721A: optical decay
  78. GRB 050721: optical afterglow confirmed
  79. GRB050721A: Swift-BAT detection of a weak burst
  80. GRB 050717: PROMPT RcIc Observations
  81. GRB050714b: Radio Observation
  82. GRB050712: Radio Observations
  83. GRB050713a: Radio Observation
  84. GRB 050712, Tautenburg optical afterglow observations
  85. Swift-BAT detection of a possible GRB
  86. GRB 050714B: VLT R-band observations
  87. GRB 050717: Additional LCO observations
  88. GRB050717
  89. GRB 050716; J-band observations
  90. Konus-Wind observation of GRB 050717
  91. GRB 050717: LCO near-IR observations
  92. Swift/UVOT Observations of GRB 050717
  93. GRB 050717: Swift-BAT refined analysis
  94. GRB050717: Swift XRT position
  95. Swift detection of GRB 050717
  96. Swift UVOT Observations of GRB 050716
  97. GRB 050716: Lulin B and R band optical observations
  98. GRB050716, optical observation
  99. GRB050716: Faulkes North Telescope observation
  100. Konus-Wind observation of GRB 050713A

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