Skip to main content
New! CHIME and DSA-110 FRB Notices, IceCube Notices and Schema v6.1.1. 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"
  1. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  2. GRB 071018: Mercator Telescope optical observations
  3. Swift autonomous slewing re-enabled
  4. GRB071010b: optical observations
  5. GRB 071018: SARA observations
  6. GRB 071018: Swift-XRT observation
  7. GRB 071017 - Swift XRT observations
  8. VLA radio observation of GRB 071018
  9. GRB071018: Correction to the GCN 6936
  10. GRB071018: Correction to the GCN 6936
  11. GRB071018: Correction to the GCN 6936
  12. GRB071018: Correction to the title of the GCN 6936
  13. GRB 071018: Possible OT from Xinglong TNT observation
  14. GRB 071010B: Light Curve Break Confirmed
  15. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  16. GRB 071018, Swift-BAT refined analysis
  17. GRB 071018?: Swift detection of a possible burst
  18. GRB 071010B: Suzaku WAM observation of the prompt emission
  19. GRB 071013: 3rd TLS Epoch - constraints on variability
  20. GRB 071013: TNT optical data refined analysis
  21. GRB 071010B: Keck/DEIMOS emission-line redshift
  22. GRB 071017: a SHORT GRB detected by INTEGRAL
  23. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  24. GRB071013: optical observations
  25. GRB 071010B: Optical observations of EST
  26. GRB 071010B: TLS 3rd Epoch - finally a break??
  27. GRB 071011: MITSuME Optical Observations
  28. GRB 070920A: deep optical observations at the NOT
  29. GRB 071010B: Photometry after 1.6 days
  30. GRB 071010B: Keck/LRIS Photometry
  31. GRB 071010B: TLS 2nd Epoch, refined analysis
  32. GRB 071013: TLS Upper Limit
  33. Correction to GCN circular no. # 6915 for GRB 071010B
  34. VLA detection of radio afterglow of GRB 071010B
  35. VLA non-detection of GRB 071011
  36. GRB 071013: Optical observations
  37. GRB 071013: optical observations at NOT
  38. GRB 071013, Swift-BAT refined analysis
  39. GRB071013: optical limit
  40. GRB071010B, BVRcIc field calibration
  41. GRB 20071013: Xinglong TNT optical Upper Limit
  42. GRB 071013: Swift detection of a burst
  43. GRB 071010C Swift-BAT detection of a burst
  44. GRB 071011: Optical Limit after 13.95hrs
  45. GRB 071011: Xinglong TNT Optical afterglow observations
  46. GRB 071010B correction to GCN 6892 optical observations
  47. GRB 071011: Swift-XRT refined analysis
  48. VLA non-detection of GRB 071010A
  49. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  50. GRB 071011, Optical afterglow
  51. GRB 071011: Confirmation of P60 optical afterglow
  52. GRB 071010B: Optical Detection
  53. GRB 071011: Kanazawa Optical limits
  54. GRB 071011: P60 Optical Afterglow Candidate
  55. GRB 071011: MARGE Optical Limits
  56. GRB 071010B: Super-LOTIS upper limit
  57. GRB 071010B optical photometry
  58. GRB 071011: XRT afterglow detection
  59. GRB 071010B: Keck/LRIS Spectroscopy
  60. GRB 071011, Swift-BAT refined analysis
  61. GRB 071010B: Gemini Spectroscopic Observations
  62. GRB 071011: Early Super-LOTIS Observations
  63. GRB 071011: NAYUTA Optical Observation
  64. GRB 071010A: Continued Keck Imaging
  65. GRB 071010B: Bright OT confirmed with TLS
  66. GRB 071011: Optical afterglow candidate
  67. GRB 071011: Swift detection of a burst
  68. Optical Observation: GRB 071010
  69. Optical observations: GRB 071010A
  70. Konus-Wind observation of GRB 071010B
  71. GRB071010B: Swift/XRT detection
  72. GRB 071010B, Swift-BAT refined analysis
  73. GRB 071010A: bright NIR afterglow
  74. GRB 071006, Swift-BAT refined analysis
  75. GRB071008: optical observations
  76. GRB 071010B possible optical transient
  77. GRB 071010A: Keck/LRIS Photometry
  78. GRB 071010B: Swift detection of a burst
  79. GRB 071010: Swift-XRT observation
  80. GRB 071008, Swift-BAT refined analysis
  81. GRB 071010, Swift-BAT refined analysis
  82. Konus-Wind observation of GRB 071006
  83. GRB071008: Swift-XRT observation
  84. GRB 071010 REM NIR observations
  85. GRB 071010: Keck/LRIS Spectroscopy
  86. GRB 071010: TAROT La Silla observatory photometry of the afterglow
  87. GRB 071010: Rapid PROMPT Detections
  88. GRB 071010: Keck Observations of the Afterglow
  89. GRB 071010: TAROT La Silla observatory detection of the afterglow
  90. GRB 071010: Swift detection of a burst
  91. GRB 071006 Swift-BAT detection of a burst
  92. GRB071008: IAC80 observation
  93. GRB 071008: Swift detection of a burst
  94. GRB 071003: XRT refined analysis
  95. GRB070920A: MAGIC telescope GeV observation
  96. Radio detection of GRB 071003 with the VLA
  97. GRB 070810B: further XRT analysis
  98. GRB 071003: VLT spectroscopy
  99. GRB 071003: Keck spectroscopy
  100. Konus-Wind observation of GRB 071003

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