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"
  1. SGR 0501+4516: Decline in Activity
  2. SGR 0501+4516: Proximity to supernova remnant HB9
  3. Enhanced Swift-XRT position of SGR 0501+4516
  4. SGR 0501+4516: GMRT Radio Observation at 618 MHz
  5. SGR 0501+4516: Swift XRT measure of the spin period
  6. GRB080823: Fermi Gamma-ray Burst Monitor detection
  7. GRB 080824: Fermi Gamma Ray Burst Monitor detection
  8. GRB 080825B: pseudo-z= 0.83 from prompt emission spectrum
  9. Konus-Wind observation of GRB 080825B
  10. GRB080825C: GLAST Burst Monitor detection
  11. GRB 080825B: Swift-XRT team analysis
  12. SGR 0501+4516: Fermi GBM (formerly GLAST Burst Monitor) observations of three exceptionally intense outbursts
  13. Soft Gamma Repeater SGR 0501+4516: GBM Detection of multiple bursts
  14. GRB080825: Afterglow confirmation and redshift estimate
  15. Suzaku ToO Observation of SGR 0501+4516
  16. GRB 080825B - optical counterpart candidate
  17. SGR 0501+4516: radio pulsar searches with GBT and WSRT
  18. GRB 080825B: GRB Localization by SuperAGILE
  19. Konus-Wind observations of new SGR 0501+4516
  20. INTEGRAL ToO Observation of SGR0501+4516
  21. Radio Detection of SGR 0501+4516
  22. SGR 0501+4516: MDM Optical Observations
  23. GRB 080822B, Swift-BAT refined analysis
  24. SGR 0501+4516: Astrotel-Caucasus optical observations
  25. SGR 0501+4516: UKIRT detection of possible infra-red counterpart
  26. SGR 0501+4516: WSRT Radio Observations
  27. Trigger 321551: Continued Large Flaring of SGR 0501+4516
  28. GRB 080822B: MASTER optical observation
  29. New Soft Gamma Repeater 0501+4516 (GRB 080822): GLAST Burst Monitor detection
  30. SGR 0501+4516: optical observations
  31. Swift Trigger 321481: A Large Flare from SGR 0501+4516
  32. SGR 0501+4516: Swift-BAT refined analysis of the 3 discovery events
  33. Discovery of the Spin Period of the New Soft Gamma Repeater SGR 0501+4516
  34. GRB 080822B: Swift detection of a burst
  35. GRB080818B: GLAST Burst Monitor detection
  36. Third event from SGR 0501+4516
  37. GRB 080822 (SGR 0501+4516): archival optical observations
  38. New Soft Gamma Repeater 0501+4516 was GRB 080822
  39. GRB 080822: Swift detection of a short burst
  40. GLAST Burst Monitor detection of a GRB: 080816B
  41. GLAST Burst Monitor detection of GRB 080818
  42. GLAST Burst Monitor detection of GRB080817B
  43. GLAST Burst Monitor detection of GRB 080817
  44. GLAST Burst Monitor detection of GRB080816
  45. GRB080810 - optical observations
  46. GRB080810: optical observations
  47. GLAST Burst Monitor detection of GRB 080812
  48. Radio detection of GRB 080810 with the VLA
  49. GRB 080810: RTT150 optical observations
  50. GRB 080810: Konus-Wind and Swift/BAT joint spectral analysis
  51. GLAST Burst Monitor detection of GRB 080810
  52. GRB 080810: Liverpool and Faulkes North observations
  53. GRB 080810: RTT150 optical observations
  54. GRB080810: MITSuME optical observation
  55. First GLAST Burst Monitor GRB Circulars
  56. GRB 080810: Swift/UVOT Refined Analysis
  57. GRB 080810: optical observations
  58. GRB 080810: Liverpool Telescope observations
  59. GRB 080810: D50 optical observation
  60. GRB 080810: Kanazawa optical observation
  61. GRB 080810: OSN follow-up
  62. GRB 080810: Observations from NOT
  63. GRB 080810: RTT150 optical observations
  64. GRB 080810: Swift-XRT Team refined analysis
  65. GRB 080810: Enhanced Swift-XRT position
  66. GRB 080810: KANATA optical-NIR observation, update
  67. GRB 080810: ROTSE-III Prompt Detection of Optical Counterpart
  68. GRB 080810: Keck/HIRES Spectroscopy
  69. GRB 080810, Swift-BAT refined analysis
  70. GRB 080810 : optical observation with KANATA
  71. GRB 080810: Swift detection of a burst with a bright optical afterglow
  72. GRB 080723B: GROND upper limits
  73. GRB 080723B: XMM-Newton observation
  74. GRB 080805: VLT redshift update
  75. GRB 080805: Faulkes Telescope South optical observations
  76. GRB 080804: GROND observations
  77. GRB 080727B: Late VLT imaging
  78. GRB 080804: ATCA Radio Observations
  79. GRB 080805: Swift-XRT Refined Analysis
  80. GRB 080805: Swift/UVOT Upper Limits
  81. GRB 080804: Swift-XRT Refined Analysis
  82. GRB 080804: Swift/UVOT Refined Analysis
  83. GRB 080805, Swift-BAT refined analysis
  84. GRB 080804, Swift-BAT refined analysis
  85. GRB 080804: Enhanced Swift-XRT position
  86. GRB080804: Gemini South redshift confirmation
  87. GRB 080804: Faulkes Telescope South observations
  88. GRB080805 optical limit by "Pi of the Sky"
  89. GRB 080805: VLT redshift
  90. GRB 080805: Afterglow confirmation
  91. GRB 080805: GROND detection of possible afterglow
  92. GRB 080805: Swift detection of a burst
  93. GRB 080804: UVES redshift
  94. GRB 080804: Swift detection of a burst with optical afterglow
  95. GRB 080804: ROTSE-III Detection of Optical Counterpart
  96. GRB 080802: Swift/UVOT Upper Limits
  97. GRB 080802: Swift-XRT Refined Analysis
  98. GRB 080802: UVI Telescope Upper Limit
  99. GRB 080802, Swift-BAT refined analysis
  100. GRB 080802: Swift detection of a probable 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