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"

19548 results found.

  1. GRB 061218, Swift-BAT refined analysis
  2. GRB061217: VLT NIR observations
  3. GRB 061218, SMARTS optical/IR observations
  4. GRB 061218: REM prompt observations
  5. Swift triggers (#251863) on a possible burst
  6. GRB061217: Swift/UVOT refined analysis.
  7. GRB 061217, Further Swift-BAT refined analysis of the short hard burst
  8. GRB 061217, Swift-BAT refined analysis
  9. GRB 061217: Magellan Observations
  10. GRB 061217: REM prompt observations
  11. GRB 061217: ROTSE-III Optical Limits
  12. GRB061210: Swift/UVOT observations
  13. GRB 061210: Swift XRT analysis - Possible counterparts
  14. GRB 061214(?): Swift detection of a possible burst
  15. GRB 061210: Gemini/GMOS Observations
  16. GRB 061126: Radio Observations
  17. GRB061210: Radio Observations
  18. Optical Afterglow observations of GRB 061126
  19. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  20. GRB 061202: TORTOREM optical upper limits
  21. GRB 061201: VLT optical decay
  22. GRB 061201: SOAR Confirmation of Candidate Afterglow
  23. GRB061202: FRAM early follow-up limit
  24. GRB061202 optical limit by "Pi of the Sky"
  25. GRB061202: optical/NIR observations with REM
  26. GRB061202: Swift/UVOT Upper Limits
  27. GRB 061202: Swift detection of a burst
  28. GRB 061201: VLT optical observations
  29. GRB 061201: Swift detection of a short hard burst
  30. INT+WFC observations of GRB 061126
  31. RHESSI Spectrum of GRB061126
  32. GRB061126: Optical afterglow observations from MIRO
  33. GRB061126: Optical afterglow observations from MIRO
  34. GRB 061126 : SDSS Pre-Burst Observations
  35. GRB 061126: Swift/UVOT Observations
  36. GRB 061126: Early Detection of the IR Afterglow
  37. GRB 061122: Candidate Optical Afterglow
  38. GRB061122: Swift/UVOT Optical Observations
  39. GRB061121: P60 Observations
  40. Radio detection of GRB 061121
  41. GRB061122: Swift-XRT position
  42. Konus-Wind observation of GRB 061122
  43. Swift-BAT trigger 239987 is not a GRB
  44. GRB 061121: Swift/UVOT Observations
  45. GRB061121, optical observation
  46. GRB 061121: Optical observation at the KANATA 1.5m telescope
  47. GRB061121: Spectroscopic Redshift
  48. GRB 061121: Swift detection of a bright burst with an optical counterpart
  49. GRB 060605: NIR Observations
  50. GRB 050915B: optical afterglow
  51. GRB061110A: Correction to GCN5817
  52. Swift/UVOT Upper Limits for GRB061110b
  53. Swift/UVOT Upper Limits for GRB061110a
  54. GRB061110B: Optical observations at Crni Vrh
  55. GRB 061110B: Swift-UVOT Initial Observation
  56. GRB 061110B: TAROT Calern observatory optical observations
  57. GRB 061110B: Swift detection of a burst
  58. GRB 061110: Candidate confirmed
  59. GRB 061110: ROTSE-III Optical Limits
  60. GRB 061110: Swift detection of a burst
  61. GRB061110A - Optical Non-detection
  62. GRB 061109: TAROT Calern observatory optical observations
  63. GRB 061027: TAROT La Silla observatory optical observations
  64. GRB 061028: Swift/XRT Astrometry Correction
  65. GRB 061102: Swift/UVOT Magnitude Upper Limits
  66. GRB061102B: Super-LOTIS observations
  67. GRB 061028: Optical R passband observations
  68. GRB 061102B: Swift detection of a possible burst
  69. GRB 061102: Swift detection of a burst
  70. GRB 061028: VLA Observation
  71. GRB 061004: Swift/XRT Astrometry Correction
  72. GRB 060801: Swift/XRT Astrometry Correction
  73. GRB 061028: Futher P200 Observations
  74. GRB 061028: P200 Observations
  75. GRB 061028: SARA upper limit
  76. GRB 061028: z band imaging
  77. GRB061028: XRT refined analysis
  78. GRB 061028: Swift/UVOT Observations
  79. GRB 061028: TAROT Calern observatory optical observations
  80. GRB 061028: Swift detection of a burst
  81. GRB 061027, Swift refined analysis of a possible burst
  82. GRB 061027: Swift detection of a possible burst
  83. GRB061025: Swift/UVOT observations
  84. GRB 061025: REM observations
  85. GRB 061025: ROTSE-III Optical Limits
  86. GRB 061021: Swift/UVOT Observation
  87. GRB 061021: Swift detection of a burst
  88. GRB 061019: SARA upper limit
  89. GRB 061019: Swift/UVOT upper limit
  90. GRB 061019: TAROT La Silla observatory optical observations
  91. GRB 061019: REM K-band candidate afterglow
  92. GRB 061006: astrometry-corrected XRT position
  93. GRB 061007: ATCA Radio Observations
  94. GRB061007: Swift UVOT followup observations
  95. GRB 061006: optical afterglow
  96. GRB 061007: OA fading and VLT redshift
  97. GRB 061007: Magellan Spectroscopy
  98. GRB 061006: Swift/UVOT optical observations
  99. GRB 061007: Swift detection of a burst with an optical counterpart
  100. GRB 061006: VLT observation

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