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"

37493 results found.

  1. GRB 141028A: Fermi-LAT detection
  2. GRB 141026A: GTC spectroscopy
  3. GRB 141026A: Skynet PROMPT-CTIO/Yerkes-41 Observations
  4. GRB 141026A: SAO RAS Zeiss-1000 observations
  5. GRB 141026A: Continued RATIR Optical and NIR Observations
  6. GRB 141026A: Swift/UVOT Upper Limits
  7. GRB 141004A: Continued RATIR Late Time Optical and NIR Observations
  8. GRB 141026A: Continued RATIR Optical and NIR Observations, Afterglow Detection
  9. GRB 141026A: Swift-XRT refined Analysis
  10. GRB 141026A: Swift-BAT refined analysis
  11. Fermi Gamma-ray Burst Monitor trigger 141026452 is not a GRB
  12. GRB 141026A: MASTER early optical observations
  13. GRB 141026A: Enhanced Swift-XRT position
  14. GRB141026A: Deep P200 optical imaging
  15. GRB 141026A: 1.23m CAHA I-band observations
  16. GRB 141026A: GROND observations
  17. GRB 141026A: RATIR Optical Observations
  18. GRB 141026A: P60 early observations
  19. GRB 141026A: Swift detection of a burst
  20. Fermi Gamma-ray Burst Monitor trigger 141025734 is not a GRB
  21. GRB 141020A: AAO optical upper limit
  22. GRB 141020A: Khureltogot optical upper limit
  23. GRB141022A: Fermi GBM Detection
  24. GRB141022B: Fermi GBM Detection
  25. GRB 141022A: Swift/UVOT Upper Limits
  26. GRB 141020A: Mondy optical observations
  27. GRB 141022A: Swift-BAT refined analysis
  28. GRB 141022A: Swift-XRT refined Analysis
  29. GRB141015A iTelescope observation
  30. GRB 141022A: GROND Detection of a possible Optical Afterglow Candidate
  31. GRB 141022A: Swift detection of a burst
  32. GRB 141004A: RATIR Late Time Optical and NIR Observations
  33. GRB 141004A: La Palma late-time observations and possible brightening
  34. GRB 141020A: Swift-BAT refined analysis
  35. GRB 141020A: Swift-XRT refined Analysis
  36. GRB 141020A: 1.4 GHZ observation
  37. GRB 141020A: Swift/UVOT Detection
  38. GRB 141020A: Enhanced Swift-XRT position
  39. GRB 141020B: MAXI/GSC detection
  40. Konus-Wind observation of GRB 141017A
  41. GRB 141020A: Swift detection of a burst with an optical counterpart
  42. GRB 141017A, Swift-BAT refined analysis
  43. GRB 141017A: GROND Afterglow Confirmation
  44. GRB 141015A: Swift-XRT afterglow confirmation and refined Analysis
  45. GRB 141017A: Swift/UVOT Detection
  46. GRB 141015A: MITSuME Akeno upper limits
  47. GRB 141017A: Swift-XRT refined Analysis
  48. GRB 141017A: Enhanced Swift-XRT position
  49. GRB 141017A: Zadko observatory - Gingin optical observations
  50. GRB 141017A: Swift detection of a burst
  51. GRB 141015A: Swift/UVOT Upper Limits
  52. GRB 141015A: MITSuME Okayama upper limits
  53. GRB 141015A: Swift-BAT refined analysis
  54. GRB 141015A: LCO-McDonald observations
  55. GRB 141015A: RATIR Optical Upper Limits
  56. GRB 141015A: Enhanced Swift-XRT position
  57. GRB 141015A: Super-LOTIS early observations
  58. GRB 141015A: ISON-NM early optical observations
  59. GRB 141015A: Swift/XRT localization
  60. GRB 141015A: Swift detection of a burst
  61. Fermi Gamma-ray Burst Monitor trigger 141014781 is not a GRB
  62. Konus-Wind observation of GRB 141011A
  63. IPN Triangulation of GRB 141011A (short/hard)
  64. GRB 141011A: Fermi GBM detection
  65. GRB 141005A: iTelescope.Net T21 Optical Observation
  66. GRB141004A: Host galaxy redshift form GTC
  67. GRB 141005A: Additional P60 imaging and afterglow confirmation
  68. GRB 141004A: Fermi GBM observation
  69. GRB 141004A: GROND observations
  70. GRB 141005A: GROND observations
  71. Konus-Wind observation of GRB 141005A
  72. GRB 141004A: Swift-XRT refined Analysis
  73. GRB 141005A: Swift-XRT refined Analysis
  74. GRB 141005A: Swift/UVOT Upper Limits
  75. GRB 141005A: Swift-BAT refined analysis
  76. GRB 141004A: Swift-BAT refined analysis
  77. GRB141004A: NOT imaging and spectroscopy
  78. GRB 141004A: Swift/UVOT Detection
  79. GRB 141005A: Fermi GBM Detection
  80. GRB 141005A: Enhanced Swift-XRT position
  81. GRB 141004A: RATIR Optical Observations
  82. GRB 141004A: Monte Agliale Observatory optical observations
  83. GRB 141005A: RATIR Optical Observations
  84. GRB 141005A: P60 probable afterglow deteaction
  85. GRB 141004A: Enhanced Swift-XRT position
  86. GRB 141005A: Swift detection of a burst
  87. GRB 141004A: TNG photometric and spectroscopic observations
  88. GRB 141004A: 1.23m CAHA optical observations
  89. GRB 141004A: a long GRB detected by INTEGRAL
  90. GRB 141004A: Swift detection of a burst with an optical counterpart
  91. GRB 140928A: Swift-XRT follow-up observations
  92. GRB 140930B: MASTER early possible OT detection
  93. GRB 140930B: Gemini South Spectroscopy
  94. GRB 140930B: GROND observations
  95. GRB 140930A/MAXI J2259+524: MASTER optical observations
  96. GRB 140930B Swift-BAT refined analysis
  97. GRB 140930B: Swift/UVOT Upper Limits
  98. Konus-Wind observation of GRB 140930B
  99. GRB 140930B: Keck NIR imaging
  100. GRB 140930B: Swift-XRT refined Analysis

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov