Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"
  1. GRB050730: confirmation of redshift
  2. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  3. GRB 050730, SMARTS optical/IR afterglow observations
  4. GRB 050730 : Planned XMM-Newton observation
  5. GRB050730: Liverpool Telescope optical observations
  6. GRB 050730, optical candidate
  7. GRB050730: Swift-BAT detection of a weak burst
  8. GRB 050713A: Swift XRT extended light curve
  9. GRB 050709: PROMPT Rc Observations
  10. GRB050713b: Maidanak optical observations
  11. GRB 050724: Secure Host Redshift from Keck
  12. GRB 050724: WHT optical observations
  13. GRB050726: Swift UVOT observations
  14. GRB 050724: Chandra Observations of the X-ray Afterglow
  15. GRB050724: Refined Radio Position
  16. GRB050713: analysis of the XMM-Newton observation
  17. GRB 050724, SMARTS optical/IR afterglow observations
  18. GRB 050726, SMARTS optical/IR observations
  19. Swift-BAT trigger 147918 is not a real GRB
  20. GRB 050727: RTT150 optical observations
  21. GRB050724: VLT observations of the variable source
  22. GRB050727: KAIT optical limit
  23. GRB050709: Second Epoch Chandra Observation
  24. GRB 050726: PROMPT Rc Observations
  25. GRB050709: Second Epoch Chandra Observation
  26. GRB 050724: dust-scattered X-ray halo detected in SWIFT/XRT observation
  27. GRB050724: Further Radio Observations
  28. GRB 050726: early Swift XRT analysis results
  29. GRB050726: Swift-BAT detection of a weak burst
  30. GRB 050724: Optical Variability in Nearby Galaxy
  31. GRB 050724: J-band observations
  32. GRB 050724: GMOS Imaging and Spectroscopy
  33. GRB 050724: SWIFT XRT refined position
  34. RXTE ASM Detection of GRB050724
  35. GRB050724: Radio Observation
  36. GRB 050724: spectroscopy of object in the XRT error circle
  37. GRB 050724: Optical limit
  38. GRB 050724: optical and near-IR observations
  39. GRB 050724: Optical imaging/astrometry
  40. GRB 050724: RTT150 optical observations
  41. GRB 050724: Swift/UVOT Upper Limit
  42. GRB 050724: early Swift XRT analysis results
  43. GRB 050724 : Lulin early R-band monitoring observations
  44. GRB050724: Refined analysis of the Swift-BAT possible short burst
  45. GRB 050724: possible host galaxy in DSS
  46. GRB050724: a short-burst detected by Swift
  47. Swift-BAT trigger 147325 is not due to a real GRB
  48. GRB050723: XRT distributed coordinates are not related to the burst
  49. GRB 050721: early afterglow light curve
  50. GRB 050721A: Swift-BAT refined analysis
  51. Correction to GCN Circ 3474 on GRB050525A
  52. GRB 050721A: Early Swift XRT analysis results
  53. GRB050721A: optical decay
  54. GRB 050721: optical afterglow confirmed
  55. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  56. GRB 050721a: Optical Observations
  57. GRB050721A: Swift-BAT detection of a weak burst
  58. GRB 050709: Refined Spectral and Temporal Properties
  59. GRB 050717: PROMPT RcIc Observations
  60. GRB050714b: Radio Observation
  61. GRB050712: Radio Observations
  62. GRB 050714a: Refined XRT analysis and afterglow confirmation
  63. GRB050713a: Radio Observation
  64. Swift-BAT trigger 146731 is not a real GRB
  65. GRB 050712, Tautenburg optical afterglow observations
  66. Swift-BAT detection of a possible GRB
  67. GRB 050714B: VLT R-band observations
  68. GRB 050717: Additional LCO observations
  69. GRB050717
  70. GRB 050716; J-band observations
  71. Konus-Wind observation of GRB 050717
  72. GRB 050717: LCO near-IR observations
  73. Swift/UVOT Observations of GRB 050717
  74. GRB 050717: Swift-BAT refined analysis
  75. GRB 050717: Refined XRT analysis.
  76. GRB050712: optical limits
  77. GRB050717: Swift XRT position
  78. Swift detection of GRB 050717
  79. GRB 050716 - UKIRT identification of candidate afterglow
  80. Swift UVOT Observations of GRB 050716
  81. GRB 050716: Refined XRT analysis.
  82. GRB050716: Refined analysis of the Swift-BAT burst
  83. GRB 050716: Lulin B and R band optical observations
  84. GRB050716, optical observation
  85. GRB 050716: Optical Observations
  86. GRB050716: Faulkes North Telescope observation
  87. GRB050716: Correction to sign in XRT coordinate
  88. Swift/BAT detection of GRB 050716
  89. GRB050715: Refined analysis of the Swift-BAT burst
  90. GRB 050715: Swift-BAT detection
  91. Swift UVOT Observations of GRB 050714B
  92. Konus-Wind observation of GRB 050713A
  93. GRB 050714B: refined XRT analysis
  94. GRB 050713b: RTT150 optical observations
  95. GRB 050714B: candidate afterglow does not fade
  96. GRB050714B: Refined analysis of the Swift-BAT burst
  97. GRB 050714B: optical afterglow
  98. Swift detection of a long transient (GRB 050714B?)
  99. GRB 050709: optical afterglow candidate
  100. GRB 050714, R-band candidate

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