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"

45468 results found.

  1. GRB 051021: Optical observations
  2. GRB 051021: ROTSE-III Confirmation of Optical Counterpart
  3. GRB 051021: Optical observations and candidate afterglow
  4. Swift-BAT trigger 160640 is not a real GRB
  5. GRB051021: A GRB Localized by HETE
  6. Swift-BAT trigger 160619 is not a GRB
  7. Swift-BAT triggered on a posible CR Shower or possible GRB
  8. GRB 050502b: Optical limit
  9. GRB 051016b: Optical limit
  10. Afterglow candidate of GRB 051016B observed at Lulin
  11. GRB 051016b: Gemini Near IR Observations
  12. GRB 051016A: Swift/UVOT upper limits
  13. GRB 051016B: refined analysis of the Swift/XRT data
  14. GRB 051016B: Swift/UVOT detection
  15. GRB 051016B,optical observation
  16. GRB 051016B : Optical follow-up at Lulin
  17. GRB 051016B: Refined analysis of the Swift-BAT burst
  18. GRB 051016B: Swift detection of a soft burst
  19. GRB 051016: Swift-BAT refined analysis
  20. GRB051016 XMM-Newton observation
  21. GRB051016: Swift XRT refined analysis.
  22. GRB051016: Planned XMM-Newton observation
  23. GRB 051016: LCO optical and near-IR imaging
  24. GRB 051016: PROMPT Observations
  25. GRB051016: Swift detection of a burst
  26. Photometric calibration of Swift/UVOT and Re-analysis of Swift/UVOT GRB 050922C data
  27. GRB051006: optical observations
  28. GRB 051012: Swift-BAT detection of burst yesterday
  29. Swift trigger 159578 is not a burst
  30. Swift-BAT Trigger 159578 is a possible burst
  31. GRB050805A: Rc optical observations
  32. GRB 051006: Swift/UVOT Upper Limits
  33. IBAS Alert 2675 : not a GRB
  34. GRB051008: optical candidate
  35. GRB 051008: - a high redshift high-luminosity burst?
  36. GRB 051008 - a low redshift low-luminosity burst?
  37. IBAS Alert 2673: not a real GRB
  38. GRB051011: bright nebulae near error box
  39. GRB051008: optical observation
  40. GRB051008: Swift XRT refined analysis
  41. GRB051008 - Swift UVOT upper limits
  42. Konus-Wind observation of GRB 051008
  43. GRB051008: Final refined analysis of the Swift-BAT burst
  44. GRB 051008: R-band upper limit
  45. GRB051008: Refined analysis of the Swift-BAT burst
  46. GRB051008: Radio Observation
  47. GRB 051008: Swift XRT position
  48. GRB 051008, optical observations
  49. GRB 051008: early Swift XRT analysis
  50. GRB 051008: Swift UVOT Candidate
  51. GRB051008: Swift-BAT detection of a bright burst
  52. GRB 051006: P60 Observations
  53. grb test
  54. GRB 051006: XRT refined analysis
  55. Swift-BAT trigger 158700 is a probable Cosmic Ray Shower Event
  56. GRB 051006: optical observations at Sierra Nevada
  57. GRB051006: Refined analysis of the Swift-BAT burst
  58. GRB 051006: XRT position
  59. GRB051006: Swift detection of a burst
  60. GRB 050906, summary of radio observations
  61. Swift-BAT triggers 158261 and 158262 Retraction
  62. GRB051001: Swift UVOT Upper Limits
  63. GRB 050925: Second Epoch WSRT Radio Observations
  64. GRB 051001: Swift XRT refined analysis
  65. GRB 051001, optical observations at Mt. John
  66. GRB 051001: I-band limit
  67. GRB 051001: AAT infra-red observations
  68. GRB 051001: Swift-BAT refined analysis
  69. GRB 051001: Swift Detection of a Burst
  70. GRB 051001: ROTSE-III Optical Limits
  71. GRB050908: optical observations
  72. GRB050922C: optical observation
  73. GRB050922B: optical limit
  74. GRB 050922C: further VLT observations
  75. GRB 050820A: NIR photometry at the TNG
  76. GRB050922C: UVES/VLT high resolution spectroscopy
  77. GRB050925: Swift/XRT limits
  78. GRB/SGR 050925: IR Observations
  79. GRB050922C - Swift UVOT preliminary analysis
  80. GRB 050922C: break in the lightcurve
  81. GRB 050925: WSRT Radio Observations
  82. GRB050925: Swift UVOT upper limits
  83. Refined analysis of the Swift-BAT soft short burst
  84. GRB 050925 : I-band observation at Xinglong observatory
  85. GRB050925: Faulkes Telescope North R-band limit
  86. GRB050925: Swift-BAT detection of a short burst
  87. GRB 050922B: Correction to BAT refined analysis, longer burst
  88. GRB050922C: TNG spectroscopic observations
  89. GRB050922B: refined XRT analysis
  90. Konus-Wind observation of GRB 050922C
  91. GRB 050922C: Refined redshift
  92. GRB050922B: Swift UVOT early upper limits.
  93. GRB OT observation
  94. GRB050922C: observation at MonteBoo
  95. INT 2.5m limit for GRB050922B
  96. GRB 050922B: optical limit
  97. GRB050922C: Optical Observations
  98. GRB 050922C: Swift XRT refined analysis
  99. HETE Fregate observations of GRB 050922C
  100. GRB 050922C: Swift-BAT refined analysis

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