Skip to main content
New! CHIME and DSA-110 FRB Notices, IceCube Notices and Schema v6.1.1. 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. GRB 060604: BAT refined analysis
  2. GRB 060604A: ROTSE-III Optical Limits
  3. GRB 060604: Swift detection of a burst with possible optical counterpart
  4. GRB 060602A: Swift-BAT Refined Analysis: Correction
  5. GRB 060602B: XMM-Newton Survey Source
  6. GRB 060602B: Swift-XRT Refined Analysis
  7. GRB 060602B: Swift-BAT Refined Analysis
  8. GRB 060602B: Swift/UVOT observations
  9. GRB 060602A: Swift-BAT Refined Analysis
  10. GRB 060602B: RTT150 optical observations
  11. GRB 060211A : WIDGET simultaneous optical observations
  12. GRB060602A: optical observations(/transient?)
  13. GRB 060526: Tautenburg Second Epoch Observations
  14. GRB060602A: Bootes-IR observations
  15. GRB 060602B: Swift detection of a burst
  16. GRB060602B: Watcher observations - no OT candidate
  17. GRB060602B: BOOTES-IR candidate afterglow
  18. GRB060602 - SDSS Pre-Burst Observations
  19. GRB 060602: Swift detection of a burst
  20. GRB 060502A: Optical afterglow observations
  21. GRB 060526: Break in X-ray light curve
  22. GRB 060526: RTT150 optical observations
  23. GRB060526, optical observations
  24. GRB 051227 : WIDGET simultaneous optical observations
  25. GRB 051028 : WIDGET pre-trigger limit
  26. GRB 060526: RTT150 optical observations
  27. GRB 060526: Multiple Optical Flares
  28. GRB060526: afterglow fitting and probable jet break
  29. GRB 060526: RTT150 optical observations
  30. GRB060526: Optical counterpart from MIRO
  31. GRB060502b: optical observations
  32. GRB 060526: RTT150 optical observations
  33. GRB 060526: Tautenburg OT observation and light curve fitting
  34. GRB060526: optical observations
  35. GRB 060526: SMARTS optical/IR afterglow observations
  36. GRB060526: possible break in the optical light curve
  37. GRB 060526: REM observations
  38. GRB 060526: RTT150 optical observations, afterglow flattening
  39. GRB 060526: Optical Flare
  40. GRB 060526: MDM-2.4m Observations
  41. GRB 060526: Refined analysis of the Swift-BAT burst
  42. GRB 060526: RTT150 optical observations
  43. GRB060526: Further Swift-UVOT Observations
  44. GRB060526, optical observations
  45. GRB 060526: Magellan Redshift
  46. GRB 060526 Lulin optical observation
  47. GRB 060526: Swift/XRT Team refined analysis
  48. GRB 060526: TNG optical observations
  49. GRB 060526: ROTSE-III Observations of Optical Counterpart
  50. GRB 060526: Watcher Observations
  51. GRB060526 - SDSS Pre-burst Observations
  52. GRB 060526: Continued emission for the Swift burst
  53. GRB 060526: Swift detection of a burst with x-ray and optical afterglow
  54. GRB060505: VLT observations of the optical afterglow
  55. GRB 060413 : WIDGET simultaneous optical observations
  56. GRB 060522: Swift/UVOT Observations: Correction
  57. GRB 060522: Swift/UVOT Observations of the Optical Afterglow
  58. XMM-Newton observation of GRB060510b
  59. GRB060512: Late-Time P200 Observations
  60. GRB060522: z = 5.11 Keck-LRIS Redshift
  61. GRB 060522: Swift/XRT Team refined analysis
  62. GRB 060522: Swift-BAT Refined Analysis
  63. GRB 060522: REM NIR observations
  64. GRB 060522: TNG optical observations
  65. GRB 060522: Swift detection of a burst with possible optical afterglow
  66. GRB 060512: reanalysis of optical spectra
  67. GRB 060515: NIR observation
  68. GRB 060210: Jet Break in the XRT light curve
  69. GRB 060516: Refined analysis of the Swift-BAT burst
  70. GRB 060512: TNG optical spectroscopy
  71. GRB 060516: Swift detection of a burst
  72. GRB060515: P200 NIR Observations
  73. GRB 060505 BAT refined analysis
  74. GRB 060515 BAT refined analysis
  75. GRB 060512: TAROT optical observation
  76. GRB 060515: Swift/XRT Team refined analysis
  77. GRB 060515: Swift/UVOT Upper Limits
  78. GRB 060515: Swift/XRT position
  79. GRB 060515: Super-LOTIS Observations
  80. GRB060515: Swift/UVOT initial observation
  81. GRB 060515: TAROT optical observation
  82. GRB 060515: ROTSE-III Optical Limits
  83. GRB 060515: Swift detection of a burst
  84. VLT optical spectroscopy of GRB 060512
  85. Swift/UVOT observations of GRB060512.
  86. GRB 060512: Subaru NIR observation
  87. GRB060512: Swift XRT Team refined analysis
  88. GRB 060512: 1.54m Kuiper Observations
  89. GRB 060512: Detection of NIR afterglow
  90. GRB 060512: P60 Observations
  91. GRB 060512: Swift-BAT Refined Analysis
  92. GRB 060505 - OT candidate + galaxy spectrum
  93. GRB 060512: optical decay
  94. GRB 060512: REM NIR observations
  95. GRB060512 - SDSS Pre-Burst Observations
  96. GRB060512 Name Correction: LT Afterglow detection
  97. GRB060512: Liverpool Telescope Afterglow detection
  98. GRB 060512: Swift detection of a burst with an optical afterglow
  99. GRB 060510A: Swift/UVOT Detection of an Optical Afterglow
  100. GRB 060505: X-ray afterglow - Correction -

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