Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

36031 results found.

  1. GRB 060428B: MDM Observations
  2. GRB 060428A: PROMPT Observations
  3. GRB 060427B: MASTER optical observations
  4. GRB 060427B: IPN localization of a short hard burst
  5. GRB 060428B: Refined analysis of the Swift-BAT burst
  6. GRB 060428B: Xinglong I-band limit
  7. GRB 060428B: KAIT observations
  8. GRB060425:MASTER optical limit
  9. GRB 051117A: Bright host galaxy not confirmed
  10. GRB 060428A: Refined analysis of the Swift-BAT burst
  11. GRB 060428b : Kiso R-band limit
  12. GRB060427:MASTER optical limit
  13. GRB 060428b: Optical afterglow candidate
  14. GRB 060428B: Swift detection of a burst
  15. GRB 060427: NIR observations
  16. GRB 060428: Swift detection of a burst
  17. GRB 060427: NOT observations
  18. GRB 060427: Swift/UVOT upper limits.
  19. GRB 060427: Refined analysis of the Swift-BAT burst
  20. GRB060418: Swift XRT Team Further Refined Analysis
  21. GRB060425:MASTER survey observations
  22. GRB 060427, optical observation
  23. GRB 060427: Swift detection of a burst
  24. GRB 060425: IPN localization and KW spectrum of a short, hard burst
  25. An interactive program for GRB pseudo-redshift computations
  26. GRB060424: optical afterglow detection
  27. GRB060418: Further Analysis of MIKE Spectroscopy
  28. GRB 060424: Refined analysis of the Swift-BAT burst
  29. GRB 060424: Swift detection of a burst
  30. GRB 060421: TTT Observations
  31. GRB 060421: Swift-BAT Refined Analysis
  32. GRB 060421: Swift-XRT refined analysis
  33. GRB 060418: prediction of t_break
  34. GRB060418: optical observations
  35. Konus-Wind observation of GRB 060418
  36. GRB(?)060421:MASTER optical limit
  37. GRB(?)060421 : XRT position
  38. GRB(?) 060421: Swift detection of a burst
  39. Erratum of GCN 4983 for GRB 060418 IR follow-up
  40. GRB 060418 : IR afterglow observations
  41. GRB 060418 : Lulin Optical follow-up
  42. GRB 060418: JHKs PAIRITEL Observations of Afterglow
  43. GRB 060418: Radio Observations
  44. GRB060418, BVRcIc field calibration
  45. GRB060418: Optical Observations
  46. GRB 060418: FRAM early afterglow observation
  47. GRB 060418: Refined Analysis of the Swift-BAT burst
  48. GRB060418: Swift XRT Team Refined Analysis
  49. GRB 060418, SMARTS continuing afterglow observations
  50. GRB 060418: PROMPT Detections
  51. GRB 060418, SMARTS optical/IR afterglow observations
  52. GRB060418: Magellan/MIKE Spectroscopic Redshift
  53. GRB060418 : LT optical afterglow observation
  54. GRB 060418: REM candidate afterglow
  55. GRB 060418: Swift detection of a burst with bright x-ray and optical afterglow
  56. GRB 060413: REM NIR Observations
  57. GRB 060413: Refined analysis of the Swift-BAT burst
  58. GRB 060413: Watcher UBVR observations
  59. GRB 060413: XRT refined analysis
  60. GRB 060413: No Optical Afterglow in Swift/UVOT TDRSS Data
  61. GRB 060413: Swift detection of a burst
  62. GRB060403: optical observations
  63. GRB 060403 Optical observations
  64. GRB 060403: MITSuME optical observation
  65. GRB060403: XRT refined analysis
  66. GRB 060403: Swift/UVOT upper limits
  67. GRB 060403: Refined analysis of the Swift-BAT burst
  68. GRB 060403: Swift detection of a burst
  69. GRB 060322: LNA optical limit
  70. GRB 060218SN 2006aj: optical observations at Rozhen Observatory
  71. GRB 060323 : WIDGET simultaneous optical observations
  72. GRB 060323: Early optical observation at Xinglong
  73. GRB060218, optical observations
  74. GRB 060322: Confirmation of Swift XRT afterglow
  75. GRB 060211A: optical observation
  76. GRB060323: optical limit
  77. GRB060211B: optical observation
  78. GRB060323: NOT optical observations
  79. GRB 060322: IAC80 optical observations
  80. GRB 060322: Swift XRT afterglow candidate
  81. GRB 060323: Swift/UVOT Observations
  82. GRB 060323: optical afterglow confirmed
  83. GRB060323: NOT observations
  84. GRB 060323: Optical Observations
  85. GRB 060323: Tautenburg OT candidate retraction
  86. GRB 060323: Refined analysis of the Swift-BAT burst
  87. GRB 060323: optical observations at TNG
  88. GRB 060323: Swift XRT refined analysis
  89. GRB 060323: BVRI observations at Tautenburg, aftreglow candidate
  90. GRB 060323: Swift/XRT position
  91. GRB 060322: Refined analysis of the Swift-BAT burst
  92. GRB060323 - SDSS Pre-Burst Observations
  93. GRB 060323: Swift detection of a burst with a possible optical afterglow
  94. GRB 060322: Swift-BAT detection of a 200-sec burst
  95. GRB060219: optical observation
  96. GRB060206: optical observation
  97. GRB060218/SN2006aj: optical observations
  98. GRB 060218/SN 2006aj, LNA optical observation
  99. GRB060218: Refined photometric calibration of comparison stars
  100. GRB 060319: WHT K-band candidate afterglow

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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