Skip to main content
New! BOOM Notices and Schema v7.0.0. See news and announcements

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"

15679 results found.

  1. GRB 050801: ROTSE-III Early Afterglow Break
  2. GRB 050730: early TAROT optical observations
  3. GRB 050730: RTT150 optical observations
  4. GRB 050730, spectra and optical photometry
  5. GRB 050730: Swift XRT afterglow observations
  6. GRB050730, afterglow observations
  7. GRB050730: confirmation of redshift
  8. GRB 050730, SMARTS optical/IR afterglow observations
  9. GRB050730: Liverpool Telescope optical observations
  10. GRB 050730, optical candidate
  11. GRB050730: Swift-BAT detection of a weak burst
  12. GRB 050713A: Swift XRT extended light curve
  13. GRB050713b: Maidanak optical observations
  14. GRB 050724: WHT optical observations
  15. GRB050726: Swift UVOT observations
  16. GRB050724: Refined Radio Position
  17. GRB 050724, SMARTS optical/IR afterglow observations
  18. GRB 050726, SMARTS optical/IR observations
  19. GRB 050727: RTT150 optical observations
  20. GRB050727: KAIT optical limit
  21. GRB050709: Second Epoch Chandra Observation
  22. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  23. GRB050724: Further Radio Observations
  24. GRB050726: Swift-BAT detection of a weak burst
  25. GRB 050724: Optical Variability in Nearby Galaxy
  26. GRB 050724: Optical limit
  27. GRB 050724: optical and near-IR observations
  28. GRB 050724: Optical imaging/astrometry
  29. GRB 050724: RTT150 optical observations
  30. GRB 050724: early Swift XRT analysis results
  31. GRB050721A: optical decay
  32. GRB 050721: optical afterglow confirmed
  33. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  34. GRB 050721a: Optical Observations
  35. GRB 050709: Refined Spectral and Temporal Properties
  36. GRB050712: Radio Observations
  37. GRB050713a: Radio Observation
  38. GRB 050712, Tautenburg optical afterglow observations
  39. Swift-BAT detection of a possible GRB
  40. GRB050712: optical limits
  41. Swift detection of GRB 050717
  42. GRB 050716: Lulin B and R band optical observations
  43. GRB050716, optical observation
  44. GRB 050716: Optical Observations
  45. Swift/BAT detection of GRB 050716
  46. GRB 050713b: RTT150 optical observations
  47. GRB 050714B: candidate afterglow does not fade
  48. GRB 050714B: optical afterglow
  49. Swift detection of a long transient (GRB 050714B?)
  50. GRB 050709: optical afterglow candidate
  51. GRB 050714, optical observations
  52. GRB 050714A: ROTSE-III Optical Limits
  53. GRB 050709: Spectroscopy
  54. GRB 050713A: RAPTOR detection of early optical emission
  55. GRB050712: Swift UVOT Observation of Afterglow Emission
  56. GRB 050713B
  57. GRB050709 : Chandra source optical counterpart
  58. GRB 050712, optical observations
  59. GRB050709: Candidate X-ray Afterglow from Chandra
  60. GRB 050713, R-band observations at NOT
  61. GRB 050713: Swift detection of Bright Burst
  62. GRB 050713A: ROTSE-III Optical Limits
  63. GRB 050709: Swift UVOT and XRT observations
  64. GRB050712: UVOT candidate optical counterpart
  65. GRB 050712: Swift detection of a weak burst
  66. GRB050709, optical observations
  67. GRB050709: A Possible Short-Hard GRB Localized by HETE
  68. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  69. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  70. GRB 050626 optical observations
  71. GRB 050626: Swift XRT observations
  72. GRB 050701, optical observations
  73. GRB 050607, radio observations
  74. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  75. GRB 050525A: Swift Late-Time Decay Rate
  76. H3804: A Possible New XRB Detected by HETE
  77. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  78. XRF 050509c: Optical monitoring
  79. XRF050509c: Radio Detection
  80. GRB 050607 optical decay
  81. GRB 050607: RTT150 optical observations
  82. GRB050607: refined analysis of prompt REM observations
  83. Swift/UVOT observations of GRB050607
  84. GRB 050607: RAPTOR-S Early Optical Limits
  85. GRB050607: KAIT optical limits
  86. GRB 050525a, Mid-Infrared Observations
  87. GRB 050607: Optical decay and spectral slope
  88. GRB 050607: MDM Observations
  89. GRB050607,optical observation
  90. GRB 050607 - XRT refined data analysis
  91. Optical Afterglow of GRB 050607
  92. GRB050607 optical limit by "Pi of the Sky"
  93. GRB050607: prompt REM observations
  94. GRB050603: Fading Afterglow observed by Swift UVOT
  95. GRB 050603: Swift XRT Position
  96. GRB050603: Radio Detection
  97. GRB 050525a, SMARTS optical/IR afterglow observations
  98. GRB050528: BOOTES optical candidate (retraction)
  99. GRB050528: BOOTES optical candidate
  100. GRB050525a: Radio Observations

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov