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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"

37511 results found.

  1. GRB 050802: Swift/UVOT observations
  2. GRB 050802 : Lulin Optical follow-up observation
  3. GRB 050802: Swift-BAT refined analysis
  4. GRB050801: Optical photometry and decay index
  5. GRB 050802: XRT position
  6. GRB 050802: Swift Gamma-ray Burst
  7. GRB 050730: Preliminary Analysis of MIKE Spectrum
  8. GCN 050801: early Swift XRT analysis results
  9. GRB 050801: Swift-BAT refined analysis
  10. GRB 050801, SMARTS optical/IR afterglow observations
  11. GRB 050801, afterglow observations
  12. GRB 050730, corrected photometry and break?
  13. GRB 050801: ROTSE-III Early Afterglow Break
  14. GRB050801: Swift-BAT detection of a burst
  15. GRB 050801: ROTSE-III Detection of Possible Counterpart
  16. GRB 050730: XRT refined analysis
  17. Correction to GCN Circ 3476 on GRB050525A
  18. GRB 050730: early TAROT optical observations
  19. GRB 050726: PROMPT Rc Observations
  20. GRB 050730: RTT150 optical observations
  21. GRB 050730, spectra and optical photometry
  22. GRB050730: Refined BAT analysis of the Swift-BAT burst
  23. GRB 050730: Swift XRT afterglow observations
  24. GRB 050730 XMM-Newton observation
  25. GRB 050730: PROMPT VRcIc Observations
  26. GRB050730, afterglow observations
  27. GRB050730: confirmation of redshift
  28. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  29. GRB 050730, SMARTS optical/IR afterglow observations
  30. GRB 050730 : Planned XMM-Newton observation
  31. GRB050730: Liverpool Telescope optical observations
  32. GRB 050730, optical candidate
  33. GRB050730: Swift-BAT detection of a weak burst
  34. GRB 050713A: Swift XRT extended light curve
  35. GRB 050709: PROMPT Rc Observations
  36. GRB050713b: Maidanak optical observations
  37. GRB 050724: Secure Host Redshift from Keck
  38. GRB 050724: WHT optical observations
  39. GRB 050724: Chandra Observations of the X-ray Afterglow
  40. GRB050713: analysis of the XMM-Newton observation
  41. GRB 050724, SMARTS optical/IR afterglow observations
  42. GRB 050726, SMARTS optical/IR observations
  43. Swift-BAT trigger 147918 is not a real GRB
  44. GRB 050727: RTT150 optical observations
  45. GRB050727: KAIT optical limit
  46. GRB050709: Second Epoch Chandra Observation
  47. GRB 050726: PROMPT Rc Observations
  48. GRB050709: Second Epoch Chandra Observation
  49. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  50. GRB 050726: early Swift XRT analysis results
  51. GRB 050724: Optical Variability in Nearby Galaxy
  52. GRB 050724: J-band observations
  53. GRB 050724: GMOS Imaging and Spectroscopy
  54. GRB 050724: SWIFT XRT refined position
  55. GRB 050724: spectroscopy of object in the XRT error circle
  56. GRB 050724: Optical limit
  57. GRB 050724: optical and near-IR observations
  58. GRB 050724: Optical imaging/astrometry
  59. GRB 050724: RTT150 optical observations
  60. GRB 050724: Swift/UVOT Upper Limit
  61. GRB 050724: early Swift XRT analysis results
  62. GRB 050724 : Lulin early R-band monitoring observations
  63. GRB050724: Refined analysis of the Swift-BAT possible short burst
  64. GRB 050724: possible host galaxy in DSS
  65. Swift-BAT trigger 147325 is not due to a real GRB
  66. GRB050723: XRT distributed coordinates are not related to the burst
  67. GRB 050721: early afterglow light curve
  68. GRB 050721A: Swift-BAT refined analysis
  69. Correction to GCN Circ 3474 on GRB050525A
  70. GRB 050721A: Early Swift XRT analysis results
  71. GRB050721A: optical decay
  72. GRB 050721: optical afterglow confirmed
  73. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  74. GRB 050721a: Optical Observations
  75. GRB 050709: Refined Spectral and Temporal Properties
  76. GRB 050717: PROMPT RcIc Observations
  77. GRB 050714a: Refined XRT analysis and afterglow confirmation
  78. Swift-BAT trigger 146731 is not a real GRB
  79. GRB 050712, Tautenburg optical afterglow observations
  80. Swift-BAT detection of a possible GRB
  81. GRB 050714B: VLT R-band observations
  82. GRB 050717: Additional LCO observations
  83. GRB050717
  84. GRB 050716; J-band observations
  85. Konus-Wind observation of GRB 050717
  86. GRB 050717: LCO near-IR observations
  87. Swift/UVOT Observations of GRB 050717
  88. GRB 050717: Swift-BAT refined analysis
  89. GRB 050717: Refined XRT analysis.
  90. GRB050712: optical limits
  91. Swift detection of GRB 050717
  92. GRB 050716 - UKIRT identification of candidate afterglow
  93. Swift UVOT Observations of GRB 050716
  94. GRB 050716: Refined XRT analysis.
  95. GRB 050716: Lulin B and R band optical observations
  96. GRB050716, optical observation
  97. GRB 050716: Optical Observations
  98. GRB050716: Faulkes North Telescope observation
  99. Swift/BAT detection of GRB 050716
  100. GRB 050715: Swift-BAT detection

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