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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"

28058 results found.

  1. GCN 050801: early Swift XRT analysis results
  2. GRB 050801, SMARTS optical/IR afterglow observations
  3. GRB 050801, afterglow observations
  4. GRB 050730, corrected photometry and break?
  5. GRB 050801: ROTSE-III Early Afterglow Break
  6. GRB050801: Swift-BAT detection of a burst
  7. GRB050801: GCN XRT position is incorrect
  8. GRB 050801: ROTSE-III Detection of Possible Counterpart
  9. GRB 050730: XRT refined analysis
  10. GRB 050730: early TAROT optical observations
  11. GRB 050726: PROMPT Rc Observations
  12. GRB 050730: RTT150 optical observations
  13. Swift/UVOT photometry of GRB050730
  14. GRB 050730, spectra and optical photometry
  15. GRB 050730: Swift XRT afterglow observations
  16. GRB 050730 XMM-Newton observation
  17. GRB 050730: PROMPT VRcIc Observations
  18. GRB050730, afterglow observations
  19. GRB050730: confirmation of redshift
  20. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  21. GRB 050730, SMARTS optical/IR afterglow observations
  22. GRB 050730, optical candidate
  23. GRB050730: Swift-BAT detection of a weak burst
  24. GRB 050713A: Swift XRT extended light curve
  25. GRB 050709: PROMPT Rc Observations
  26. GRB050713b: Maidanak optical observations
  27. GRB 050724: WHT optical observations
  28. GRB050726: Swift UVOT observations
  29. GRB 050724: Chandra Observations of the X-ray Afterglow
  30. GRB050724: Refined Radio Position
  31. GRB050713: analysis of the XMM-Newton observation
  32. GRB 050724, SMARTS optical/IR afterglow observations
  33. GRB 050726, SMARTS optical/IR observations
  34. GRB050724: VLT observations of the variable source
  35. GRB050709: Second Epoch Chandra Observation
  36. GRB 050726: PROMPT Rc Observations
  37. GRB050709: Second Epoch Chandra Observation
  38. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  39. GRB050724: Further Radio Observations
  40. GRB 050726: early Swift XRT analysis results
  41. GRB050726: Swift-BAT detection of a weak burst
  42. GRB 050724: J-band observations
  43. GRB 050724: GMOS Imaging and Spectroscopy
  44. GRB 050724: SWIFT XRT refined position
  45. RXTE ASM Detection of GRB050724
  46. GRB050724: Radio Observation
  47. GRB 050724: spectroscopy of object in the XRT error circle
  48. GRB 050724: Optical limit
  49. GRB 050724: optical and near-IR observations
  50. GRB 050724: Optical imaging/astrometry
  51. GRB 050724: Swift/UVOT Upper Limit
  52. GRB 050724: early Swift XRT analysis results
  53. GRB 050724: possible host galaxy in DSS
  54. GRB050724: a short-burst detected by Swift
  55. GRB050723: XRT distributed coordinates are not related to the burst
  56. GRB 050721: early afterglow light curve
  57. GRB 050721A: Early Swift XRT analysis results
  58. GRB050721A: optical decay
  59. GRB 050721: optical afterglow confirmed
  60. GRB 050721a: Optical Observations
  61. GRB050721A: Swift-BAT detection of a weak burst
  62. GRB 050717: PROMPT RcIc Observations
  63. GRB050714b: Radio Observation
  64. GRB 050714a: Refined XRT analysis and afterglow confirmation
  65. Swift-BAT trigger 146731 is not a real GRB
  66. GRB 050712, Tautenburg optical afterglow observations
  67. Swift-BAT detection of a possible GRB
  68. GRB 050714B: VLT R-band observations
  69. GRB 050717: Additional LCO observations
  70. GRB050717
  71. GRB 050716; J-band observations
  72. GRB 050717: LCO near-IR observations
  73. Swift/UVOT Observations of GRB 050717
  74. GRB 050717: Refined XRT analysis.
  75. GRB050717: Swift XRT position
  76. Swift detection of GRB 050717
  77. GRB 050716 - UKIRT identification of candidate afterglow
  78. Swift UVOT Observations of GRB 050716
  79. GRB 050716: Refined XRT analysis.
  80. GRB 050716: Lulin B and R band optical observations
  81. GRB 050716: Optical Observations
  82. GRB050716: Faulkes North Telescope observation
  83. GRB050716: Correction to sign in XRT coordinate
  84. Swift/BAT detection of GRB 050716
  85. GRB 050715: Swift-BAT detection
  86. Swift UVOT Observations of GRB 050714B
  87. GRB 050714B: refined XRT analysis
  88. GRB 050714B: candidate afterglow does not fade
  89. GRB 050714B: optical afterglow
  90. Swift detection of a long transient (GRB 050714B?)
  91. GRB 050709: optical afterglow candidate
  92. GRB 050714: Swift XRT afterglow position
  93. GRB 050713A: XRT refined analysis
  94. GRB 050709: Spectroscopy
  95. GRB 050713A: RAPTOR detection of early optical emission
  96. GRB050713B :Swift/UVOT observations
  97. GRB050713b: XRT refined analysis
  98. GRB050712: TNG R-band observations
  99. GRB 050713A: Swift/UVOT observation
  100. GRB050712: Swift UVOT Observation of Afterglow Emission

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