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"

26540 results found.

  1. GRB 050904: TAROT optical limits
  2. GRB 050827: Swift XRT preliminary analysis results
  3. GRB 050827 : OSN 1.5m optical observations
  4. GRB 050827: P200 NIR Observations
  5. GRB050827: Swift/UVOT upper limits
  6. GRB 050827: Optical Limit
  7. GRB 050827: XRT possible afterglow detection
  8. GRB050824: Maidanak optical limits
  9. GRB050827: RTT150 optical observations
  10. GRB 050827: Swift-BAT refined analysis
  11. GRB050827: Swift-BAT detection of a burst
  12. Subaru Observations of GRB050724
  13. GRB050824, HETE-2 Observation
  14. GRB 050826: Swift XRT preliminary analysis results
  15. GRB 050826: BAT refined analysis
  16. GRB050826: Swift/UVOT early upper limits
  17. GRB050824: First 2 hours of power low optical decay?
  18. GRB050826: Swift-BAT detection of a long burst
  19. GRB050824: CORRECTION to UVOT observing times
  20. Swift-BAT trigger 152038 is probably not a GRB
  21. GRB050824: Swift/UVOT detection of fading afterglow
  22. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  23. GRB050824, I-band imaging
  24. GRB 050822: refined XRT analysis
  25. GRB 050824: XRT refined analysis and possible afterglow detection
  26. GRB 050824: BAT refined analysis of a soft weak burst
  27. GRB050824: MASTER:OT decay
  28. GRB050824: MASTER observation OT
  29. GRB050805a: MASTER optical candidat
  30. XRF050509c: Radio upper limits from GMRT
  31. GRB050822: Swift/UVOT upper limits
  32. GRB 050820A BAT observations of second, larger episode of emission
  33. GRB050813: Maidanak I-band observations
  34. GRB 050822: Swift-BAT refined analysis
  35. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  36. GRB050820B at FRAM
  37. Swift/UVOT UV Photometry of GRB 050820B
  38. GRB 050822: Swift detection of a long burst
  39. GRB050820a BVRcIc field photometry
  40. GRB050820B XMM-Newton observation
  41. GRB 050820a: NIR Observations by WIRO
  42. GRB 050820B: Swift XRT position
  43. GRB050820B: Refined analysis of the Swift-BAT burst
  44. GRB050820B: BAT-Swift detection of a bright GRB
  45. GRB050820: refined XRT analysis
  46. GRB 050820 Swift-BAT refined analysis
  47. GRB050819: refined XRT analysis
  48. GRB 050820: Swift detection of a GRB
  49. GRB 050819 Swift-BAT refined analysis
  50. GRB050819: Swift-BAT detection of a weak burst
  51. GRB 050817: Optical observations
  52. GRB050817: Swift-BAT Detection of a burst
  53. GRB 050814: continued fading
  54. GRB050815: XRT refined analysis
  55. GRB050815: Refined analysis of the Swift-BAT burst
  56. GRB 050815: ROTSE-III Optical Limits
  57. GRB050815: Swift-BAT detection of a burst
  58. GRB050814: Fading red source
  59. GRB050814: P60 Optical Afterglow Candidate
  60. GRB 050813: Non-fading of afterglow candidate
  61. GRB 050814: XRT refined analysis
  62. GRB050814: SWIFT/UVOT observation
  63. GRB050814: Refined analysis of the Swift-BAT burst
  64. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  65. GRB 050814: Swift XRT Afterglow Localization
  66. GRB 050814: Swift detection of a burst
  67. GRB 050813: Magellan detection of a high redshift galaxy cluster
  68. GRB050813, SDSS pre-burst observations
  69. GRB050813: SWIFT/UVOT observation
  70. GRB 050813: Swift XRT afterglow localization
  71. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  72. GRB 050730: WSRT Radio Observations
  73. GRB050805b: CrAO optical limit
  74. GRB050805a : Null detection report
  75. GRB050730, optical observations
  76. GRB050803, optical observations
  77. Retraction of Swift Trigger 149131 (GRB 050805B)
  78. GRB 050805b: OHP optical limits
  79. GRB 050805b: TAROT optical limits
  80. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  81. GRB050805a: MASTER optical candidat
  82. GRB050802: TNG optical observations
  83. GRB050803: Radio Observation
  84. GRB 050803: RTT150 optical observations
  85. GRB050801: Radio Observation
  86. GRB050730: Radio Detection
  87. GRB 050803: Keck Observations
  88. GRB 050803: Swift-BAT refined analysis
  89. GRB 050802.422: Fading of the afterglow and detection of the host
  90. GRB 050803: early Swift XRT analysis results
  91. GRB 050803: TAROT optical limits
  92. GCN GRB observation 050713A
  93. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  94. GRB 050802: Swift/UVOT optical and UV detections
  95. GRB050802: CrAO optical observations
  96. GRB050802 radio non-detection
  97. GRB 050730: OHP optical observations
  98. GRB 050802: early Swift XRT analysis results
  99. GRB 050802: Swift/UVOT observations
  100. GRB 050802: 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