Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

34207 results found.

  1. GRB050908: VLT R-band decay index.
  2. GRB 050908: Swift-BAT refined analysis
  3. GRB 050908: Optical observations
  4. Gemini Spectroscopy of GRB 050908
  5. GRB 050908: spectroscopic redshift
  6. GRB 050908: Prompt PROMPT Observations
  7. GRB 050908 : Swift XRT position
  8. GRB 050908: KAIT observations
  9. GRB 050908: P60 Confirmation of Optical Afterglow
  10. GRB 050908: Optical Observations
  11. GRB 050908: Swift detection of a burst
  12. Swift trigger 154073 is not a GRB
  13. GRB 050906: Optical observations at the Very Large Telescope
  14. GRB050904: CrAO optical observations
  15. GRB 050904 BAT refined analysis of complete data set
  16. GRB 050904: Subaru Optical Spectroscopy
  17. GRB 050906: MARGE Optical Limits
  18. GRB 050906: Swift-BAT refined analysis
  19. GRB 050906: Swift XRT upper limit
  20. GRB 050906: Radio Observations
  21. GRB 050904: Keck I-band Imaging
  22. GRB 050904: more VLT NIR observations
  23. GRB 050904: BOOTES early R-band observation
  24. GRB 050904: Did SWIFT/XRT see the prompt GRB emission ?
  25. GRB 050906: Bright galaxy in BAT error box
  26. GRB 050906: Swift/BAT Detection of a possible burst
  27. GRB 050904: More SOAR
  28. GRB 050904: photometric redshift
  29. GRB 050904: Swift/UVOT observations
  30. GRB 050904: Afterglow Astrometry
  31. GRB 050904: NIR object inside the XRT error box
  32. GRB 050904: early Swift XRT analysis results
  33. GRB 050904: SOAR YJ and PROMPT Ic Observations
  34. GRB 050904: BAT refined analysis of partial data set
  35. GRB 050904: TAROT optical measurements
  36. GRB050904: Optical Observations
  37. GRB 050904: Environmental Constraints
  38. GRB 050904: Possible High-Redshift GRB
  39. GRB 050904: SOAR/PROMPT Observations
  40. GRB 050904: TAROT optical limits
  41. Swift-BAT triggers 153461-153465 are not GRBs
  42. GRB 050824: MDM Observations
  43. GRB 050827: Swift XRT preliminary analysis results
  44. IBAS Alerts 2641 and 2642: not a real GRB
  45. Swift Trigger #152652 is not a GRB
  46. GRB 050827 : OSN 1.5m optical observations
  47. GRB 050827: P200 NIR Observations
  48. GRB 050827: Optical Limit
  49. GRB 050827: XRT possible afterglow detection
  50. GRB 050826 : Lulin R band observation
  51. GRB050824: Maidanak optical limits
  52. GRB050820A: RTT150 optical observations
  53. GRB050827: RTT150 optical observations
  54. GRB 050827: Swift-BAT refined analysis
  55. GRB 050826: Optical Candidate
  56. GRB050824, HETE-2 Observation
  57. GRB 050826: Swift XRT preliminary analysis results
  58. GRB 050826: BAT refined analysis
  59. GRB050824: First 2 hours of power low optical decay?
  60. GRB 050826: Swift XRT position
  61. GRB050826: Swift-BAT detection of a long burst
  62. GRB050824: MASTER final analysis of the OT observations
  63. Possible GRB050825:MASTER optical observations
  64. Swift-BAT trigger 152038 is definitely not a GRB
  65. Swift-BAT trigger 152038 is probably not a GRB
  66. GRB050824: decay of the XRT light curve and updated X-ray spectrum
  67. GRB050824, I-band imaging
  68. GRB050824: Radio Observations
  69. GRB 050824: Spectroscopic redshift from the VLT
  70. GRB 050822: refined XRT analysis
  71. GRB 050824: XRT refined analysis and possible afterglow detection
  72. GRB 050824: BAT refined analysis of a soft weak burst
  73. GRB050824: MASTER:OT decay
  74. GRB050824: MASTER observation OT
  75. GRB050805a: MASTER optical candidat
  76. GRB 050824: ROTSE-III Optical Limits
  77. GRB050824: Swift-BAT detection of a burst
  78. GRB 050824 optical candidate
  79. GRB050820A: RTT150 optical observations
  80. GRB050820a: PROMPT RcIc Observations
  81. GRB050815: Maidanak optical observation
  82. XRF050509c: Radio upper limits from GMRT
  83. VLT/UVES spectroscopy of GRB050820
  84. GRB 050820A BAT observations of second, larger episode of emission
  85. GRB050813: Maidanak I-band observations
  86. GRB 050822: Swift-BAT refined analysis
  87. GRB050525, GRB050607, GRB050802 BVRcIc field photometry
  88. GRB050820B at FRAM
  89. GRB050820A: RTT150 optical observations
  90. GRB 050820a - corrections to GCN 3846
  91. Swift/UVOT UV Photometry of GRB 050820B
  92. GRB 050822: ROTSE-III Prompt Optical Limits
  93. GRB 050822: Swift detection of a long burst
  94. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  95. GRB050820A: Radio Observation
  96. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  97. GRB050820a BVRcIc field photometry
  98. GRB 050820a: NIR Observations by WIRO
  99. GRB 050820B: Swift XRT position
  100. GRB050820B: Refined analysis of the Swift-BAT burst

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