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"

4055 results found.

  1. LIGO/Virgo G275697: Fermi-LAT search for a high-energy gamma-ray counterpart
  2. LIGO/Virgo G275697: REM optical/NIR observations
  3. LIGO/Virgo G275697: Konus-Wind observations
  4. LIGO/Virgo G275404: CNEOST optical observations
  5. LIGO/Virgo G275697: Swift-XRT sources
  6. LIGO/Virgo G275697: Swift/BAT data search
  7. LIGO/Virgo G275404: MASTER bright PSN detected on 27 Feb from the maximum of probability of LIGO localization
  8. LIGO/Virgo G275697: AGILE-GRID preliminary analysis
  9. LIGO/Virgo G275697: AGILE MCAL Observations
  10. LIGO/Virgo G275697: INTEGRAL search for a prompt gamma-ray counterpart
  11. LIGO/VIRGO G275697: Fermi GBM Observations
  12. LIGO/Virgo G275404: AstroSat CZTI upper limits
  13. LIGO/Virgo G275697 ANTARES search
  14. LIGO/Virgo G275697: IceCube neutrino observations
  15. LIGO/Virgo G275697: Identification of a GW CBC Candidate
  16. LIGO/Virgo G275404: Keck LRIS classification of MASTER PSN candidate
  17. LIGO/Virgo G274296: MASTER new PSN detected on 22 feb
  18. LIGO/Virgo G275404: REM optical/NIR observations
  19. LIGO/Virgo G275404: MASTER PSN detection from the maximal probability LIGO region
  20. LIGO/Virgo G275404: MASTER OT is outside LIGO error region
  21. LIGO/Virgo G275404: Keck spectrum of MASTER OT J105958.00-115756.5
  22. LIGO/Virgo G275404: Fermi-LAT search for a high-energy gamma-ray counterpart
  23. LIGO/Virgo G275404: INTEGRAL search for a prompt gamma-ray counterpart
  24. LIGO/Virgo G275404: AGILE-GRID detection of a possible gamma-ray transient
  25. LIGO/Virgo G275404: NOT Follow-up of MASTER OT
  26. LIGO/Virgo G275404: Swift-XRT sources
  27. LIGO/Virgo G275404 ANTARES search
  28. LIGO/Virgo G275404: Follow-up of MASTER OT J173532.70+103810.5
  29. LIGO/Virgo G275404: MASTER bright OT detection
  30. LIGO/Virgo G274296: P200 classification of EM candidates
  31. LIGO/Virgo G275404: Swift/BAT data search
  32. LIGO/Virgo G275404: SVOM/Mini-GWAC: Observations of initial skymap
  33. LIGO/Virgo G274296: Swift/BAT data search
  34. LIGO/Virgo G275404: AGILE-GRID preliminary analysis
  35. LIGO/Virgo G275404: Fermi GBM Observations
  36. LIGO/Virgo G275404: AGILE MCAL observations
  37. LIGO/Virgo G275404: MASTER Tunka OT detection
  38. LIGO/Virgo G275404: IceCube neutrino observations
  39. LIGO/Virgo G275404: Identification of a GW CBC Candidate
  40. LIGO/Virgo G275404: MASTER automatic follow up observations
  41. LIGO/Virgo G274296: GRAWITA-Campo Imperatore observation
  42. LIGO/Virgo G274296: Liverpool Telescope classification of EM candidates
  43. LIGO/Virgo G274296: MASTER new OT
  44. LIGO/Virgo G274296: CALET Observations
  45. LIGO/Virgo G274296: HAWC follow-up
  46. LIGO/Virgo G274296: No change to estimate of LIGO false alarm probability
  47. LIGO/Virgo G274296: PIRATE Observations
  48. IPN Triangulation of GRB 170222A (short/hard)
  49. LIGO/Virgo G274296: PS17bek is a superluminous supernova at z=0.31
  50. LIGO/Virgo G274296: J-GEM optical/NIR follow-up observations
  51. LIGO/Virgo G274296: iPTF Optical Transient Candidates
  52. LIGO/Virgo G274296: Kanata 1.5m optical spectroscopy of MASTER optical transient
  53. LIGO/Virgo G274296: Global MASTER Net PSN and QSO detection
  54. LIGO/Virgo G274296: Asiago 1.82m Optical Observations
  55. LIGO/Virgo G274296: ATLAS confirmation of the bright MASTER transient and earlier explosion date
  56. LIGO/Virgo G274296: MASTER new bright possible SN detection and inspection dinamic
  57. LIGO/Virgo G274296: PSN MASTER OT J042250.16-820415.4 is before maximum
  58. LIGO/Virgo G274296: IceCube neutrino observations
  59. LIGO/Virgo G274296: PESSTO classification of 9 Pan-STARRS transients
  60. LIGO/Virgo G274296: Fermi-LAT search for a high-energy gamma-ray counterpart
  61. LIGO/Virgo G274296: AstroSat CZTI upper limits
  62. LIGO/Virgo G274296 ANTARES search
  63. IPN Triangulation of GRB 170219A (short/hard)
  64. LIGO/Virgo G274296: Optical Observation
  65. LIGO/Virgo G274296: CNEOST imaging coverage and an optical transient
  66. LIGO/Virgo G274296: Pan-STARRS imaging and discovery of 70 transients
  67. LIGO/Virgo G274296: SWASP optical imaging coverage
  68. LIGO/Virgo G274296: Global MASTER Net two OTs detection
  69. LIGO/Virgo G274296: Global MASTER Net SN bright detection during GW error box inspection
  70. LIGO/Virgo G274296: Observations of initial skymap by project Mini-GWAC of SVOM
  71. LIGO/Virgo G274296: INTEGRAL search for a prompt gamma-ray counterpart
  72. LIGO/Virgo G274296: REM optical/NIR observations
  73. LIGO/VIRGO G274296: Fermi GBM Observations
  74. LIGO/VIRGO G274296: AGILE-GRID preliminary analysis
  75. LIGO/Virgo G274296: Identification of a GW Burst Candidate
  76. LIGO/Virgo G270580: DLT40 follow-up observation
  77. LIGO/Virgo G270580: AstroSat CZTI upper limits
  78. IPN Triangulation of GRB 170207A (long/very bright)
  79. LIGO/Virgo G270580: Gemini-South Spectroscopic Classification of Optical Transients
  80. LIGO/Virgo G270580: ANTARES upper limits
  81. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  82. LIGO/Virgo G268556: FLOYDS Spectrum of iPTF17cf/PS17fr Favors an AGN Classification
  83. LIGO/Virgo G270580: HAWC follow-up observations
  84. LIGO/Virgo G270580: Swift/UVOT follow-up of PS17yt
  85. LIGO/Virgo G270580: Fermi GBM Observations
  86. LIGO/Virgo G270580: MAXI/GSC observations
  87. LIGO/Virgo G270580: NOT observations of PS17yt
  88. LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
  89. LIGO/Virgo G270580: Asiago 1.82m observations of PS17ua and PS17yt
  90. LIGO/Virgo G270580: Swift-XRT follow-up of PS17yt
  91. LIGO/Virgo G270580: GMG photometric follow-up of PS17yt
  92. LIGO/Virgo G270580: 10.4m GTC spectroscopic observations of PS17yt
  93. LIGO/Virgo G270580: No change to estimate of LIGO false alarm probability
  94. LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
  95. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  96. LIGO/Virgo G268556: ANTARES upper limits
  97. LIGO/Virgo G270580: UL50 observations
  98. LIGO/Virgo G270580: CALET Observations
  99. LIGO/Virgo G270580: Pan-STARRS coverage and bright, rising transient PS17yt
  100. LIGO/Virgo G270580/GW170120 : Asiago observations

Advanced

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