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"

19592 results found.

  1. GRB 050219a, optical observations
  2. GRB 050219a: Refined XRT position
  3. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  4. GRB 050219: Swift-BAT detection of a burst
  5. GRB050215b: Swift UVOT Detection of Afterglow Emission
  6. GRB 050219: Prompt X-ray position
  7. GRB 050215b: XRT confirmation of IR afterglow candidate
  8. GRB050215b: P60 Optical Observations
  9. GRB 050215b: Swift XRT Source Variability
  10. GRB 050215B: candidate afterglow
  11. GRB 050215b : Lulin follow-up observation
  12. GRB 050215b, BOOTES-2 simultaneous optical observations
  13. GRB 050215B: UKIRT K-band imaging
  14. GRB 050215b: Swift XRT Observations
  15. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  16. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  17. Swift-BAT detects two bursts: GRB050215a and GRB050215b
  18. GRB050215B: ROTSE-III optical observations
  19. GRB050215A: ROTSE-III Optical Observations
  20. short/hard GRB 050202, optical observations
  21. GRB 050128: Radio observations
  22. Further analysis of the short Swift-BAT GRB 050202
  23. GRB 050202: Second epoch radio observations
  24. GRB050202: Radio Observations
  25. GRB 050202: Short burst detected by Swift-BAT
  26. SGR1806-20: Swift-BAT detection of a large normal burst
  27. GRB050128: Faulkes Telescope South observations
  28. GRB050128,optical observations
  29. GRB050126: Updated Swift XRT Position
  30. GRB 050126: Radio Observations
  31. GRB050128 Swift-BAT observations
  32. GRB 050128: Swift XRT prompt afterglow position
  33. GRB 050124: K-band afterglow observations
  34. GRB050126: MASTER optical limit for KECK OT
  35. GRB050126: Burst Parameters Measured by BAT
  36. GRB050126: MASTER optical observations
  37. GRB 050126: Prompt XRT detection and localization
  38. GRB050124: No Swift UVOT Detection of Afterglow Emission
  39. GRB 050117a: Radio Observations
  40. GRB050124,optical observation
  41. GRB050124: Updated Swift XRT Position and Fluxes
  42. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  43. GRB050124: Refined BAT position, spectral and fluence information
  44. GRB050124: Swift-BAT position of a double-peaked burst
  45. GRB050117a: Radio Observations
  46. GRB050117a: Refined analysis
  47. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  48. GRB050117b: Swift-BAT detection of a weak burst
  49. GRB050117: optical observation
  50. GRB 050117, I-band observations
  51. GRB 050117: Optical observation
  52. GRB050117: Refined XRT position
  53. GRB050117: MASTER optical observations
  54. MASTER:GRB050117 SWIFT
  55. GRB050117: Swift-BAT detection of a long multi-peaked burst
  56. GRB050117: Swift XRT Position
  57. SGR1806-20: Swift-BAT observations of two additional bursts
  58. SGR 1806-20, RHESSI observations of the 041227 giant flare
  59. SGR1806-20: RXTE-PCA observation of the 041227 super-flare
  60. GRB 041217: Optical observations
  61. SGR1806-20: Swift-BAT observation of the 041227 super-flare
  62. GRB041228: ROTSE-III Optical Observations
  63. GRB041228: Swift-BAT detection of a burst
  64. GRB041219; RXTE ASM Observations
  65. NIR Observations of GRB 041219
  66. GRB041226: ROTSE-III Optical Observations
  67. GRB041226: Swift-BAT detection of a burst
  68. GRB041223: decay of the afterglow
  69. GRB041224: ROTSE-III Optical Observations
  70. GRB 041223: XRT afterglow spectrum and light curve
  71. GRB 041223 Fluence measured by Swift-BAT
  72. GRB041224: Swift-BAT detection of a soft burst
  73. GRB041223: optical and NIR observations with REM
  74. Swift-BAT Time History of GRB041219
  75. GRB041223: Swift XRT Detection of X-ray Afterglow Emission
  76. GRB041223: ROTSE-III Optical Observations
  77. GRB041223: Swift-BAT detection of a bright long burst
  78. GRB041220: Swift-BAT burst
  79. GRB 041219 Optical Observations
  80. GRB041219c: Third Burst in One Day from Swift-BAT
  81. GRB041219b: A Swift-BAT burst
  82. Swift-BAT detection of the bright long burst GRB041219
  83. GRB041217: optical limit 30 min after GRB
  84. GRB041217: Optical Observations
  85. GRB041217: NIR and optical observations with REM
  86. GRB041217: P60 Optical Observations
  87. GRB041217: Infrared Observations
  88. GRB041217: The First GRB Located On-Board Swift
  89. GRB040916: Optical observations
  90. GRB040422: optical and NIR observations at the VLT
  91. GRB040223, improved XMM position
  92. SN 2003jd (SN/GRB?) - possible association with GRB 030929

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