Skip to main content
Due to the lapse in federal government funding, NASA is not updating this website. See the Operations FAQ for GCN impacts.
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"
  1. Swift detection of a possible burst (Trigger 284850)
  2. SN 2007bg - off-axis GRB?
  3. GRB 070704: RTT150 optical observations
  4. GRB 070704: Suzaku/WAM observation of the prompt emission
  5. Konus-Wind observation of GRB 070707
  6. Updated Swift/UVOT calibration
  7. GRB 070707: optical afterglow
  8. GRB 070707: object inside XRT error circle
  9. Swift/UVOT Observations of GRB070707
  10. Swift XRT observation of GRB 070707
  11. GRB 070707: VLT observations
  12. INTEGRAL GRB 070707 is a short hard burst
  13. INTEGRAL GRB 070707 is a short hard burst
  14. GRB 070707: A long GRB detected by INTEGRAL
  15. GRB 070707: A long GRB detected by INTEGRAL
  16. GRB 070429B: NIR Observations
  17. GRB070704: FAVOR optical observations
  18. GRB 070704 : Liverpool Telescope Observations
  19. GRB 070611: VLT observations
  20. VLA detection of GRB 070612A in C Band
  21. Konus-Wind observation of GRB 070626
  22. GRB 070704: Swift-XRT refined analysis
  23. Swift/UVOT Observations of GRB070704
  24. GRB 070704, Swift-BAT refined analysis
  25. GRB 070704: Correction to GCN Circ 6594
  26. GRB 070704: Swift detection of a burst
  27. GRB 070626: Suzaku/WAM observation of the prompt emission
  28. GRB 070626: IPN localization and Konus spectrum of a bright long burst
  29. GRB 070628 Swift-UVOT Refined Analysis
  30. GRB 070628: NIR detection of afterglow
  31. GRB 070628, Swift-BAT refined analysis
  32. GRB 070628: TAROT La Silla observatory optical observations
  33. GRB 070628: Swift XRT refined analysis
  34. GRB 070628: Watcher Observations
  35. Swift UVOT Observations of GRB 070628
  36. GRB 070628: Swift detection of a possible burst
  37. GRB 070612A: Allen Telescope Array Observations
  38. IBAS Alert n. 4638: Not a GRB
  39. OT20050728 was not an optical GRB afterglow
  40. INTEGRAL burst GRB070615: X-ray continued observations
  41. GRB 070616 : WIDGET simultaneous optical observations
  42. GRB 070616: Suzaku/WAM observation of the prompt emission
  43. IBAS Alert n.4637: not a GRB
  44. GRB 070612A: Second Epoch WSRT Radio Observations
  45. GRB070621: RTT150 optical observations
  46. GRB 070621: VLT optical observations
  47. GRB 070621: Swift/UVOT Upper Limits
  48. Keck Laser Guide Star Adaptive Optics Imaging of GRB 070621
  49. GRB 070621: Swift-BAT refined analysis
  50. WHT observations of GRB070621
  51. GRB070621: Swift XRT refined analysis
  52. GRB 070621: Gemini South optical imaging
  53. GRB 070621: UVOT-enhanced XRT position
  54. Observations of GRB070612A at Calar Alto
  55. GRB 070621: NOT observations
  56. GRB070621: OPTIMA-Burst optical upper limit
  57. GRB 070621: TAROT Calern observatory optical observations
  58. GRB 070621: Watcher Observations
  59. GRB 070621: ROTSE-III Prompt Optical Limits
  60. GRB 070621: Swift detection of a burst
  61. GMRT upper limit of GRB 070610/SWIFT J195509.6+261406 in 610 MHz
  62. GRB 070612A: TNG optical observations
  63. Swift/UVOT detection of GRB070616 optical afterglow.
  64. GRB070612A: Gemini Spectroscopic Redshift
  65. GRB 070612A: NOT observations
  66. GRB070616: Optical Observation by MITSuME Akeno
  67. GRB 070612B: Optical Observation by MITSuME Akeno
  68. GRB070616: Optical Observation by MITSuME Okayama
  69. GRB 070616, Swift-BAT further refined analysis
  70. GRB 070616: Swift XRT refined circular
  71. GRB 070612A: Possible WSRT Radio Detection
  72. GRB 070616: BTA astrometry and finding chart
  73. GRB 070616: BTA optical observations
  74. Swift/UVOT observations of GRB070616
  75. GRB 070616: TLS observation
  76. Swift XRT observations of the INTEGRAL burst GRB070615: Possible
  77. GRB 070616, Swift-BAT partial refined analysis
  78. GRB 070616: Swift detection of a burst
  79. GRB 070612B: optical observations
  80. UVOT Observations of INTEGRAL burst GRB070615
  81. VLA upper limit on GRB 070610
  82. GRB 070615
  83. GRB 070615: A long GRB detected by INTEGRAL
  84. SWIFT J195509.6+261406 (GRB 070610): further observations
  85. GRB 070612A: Super-LOTIS observations
  86. GRB 070612A: Rapid Decay
  87. GRB 070612A: Suzaku/WAM observation of the prompt emission
  88. SWIFT J195509.6+261406 / GRB 070610: OPTIMA-Burst observations
  89. GRB070612A: MITSuME Okayama Observation
  90. GRB 070612A: continued SARA observations
  91. GRB 070612A: spectral lag
  92. GRB 070611: Watcher Observations
  93. Swift Trigger 282176 is Cygnus X-1
  94. GRB 070612A: MDM Observations
  95. GRB 070612A: P60 Confirmation of Afterglow and An Underlying, Nearby
  96. GRB 070612B: SARA upper limit
  97. GRB 070612B, Swift-BAT refined analysis
  98. GRB 070612A, Swift-BAT refined analysis
  99. GRB 070612B: Swift-XRT refined analysis
  100. SWIFT J195509.6+261406 / GRB 070610: SWIFT continued observations

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