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"

4058 results found.

  1. LIGO/Virgo G270580: CALET Observations
  2. LIGO/Virgo G270580: Pan-STARRS coverage and bright, rising transient PS17yt
  3. LIGO/Virgo G270580/GW170120 : Asiago observations
  4. LIGO/Virgo G268556/GW170104: MAXI/GSC observations
  5. LIGO/Virgo G270580: A third optical transient from CNEOST
  6. LIGO/Virgo G270580: ATLAS coverage and 4 optical transients
  7. LIGO/Virgo G270580: Fermi-LAT search for a high-energy gamma-ray counterpart
  8. LIGO/Virgo G270580: Two optical counterpart candidates from CNEOST
  9. LIGO/Virgo G270580: INTEGRAL search of temporally coincident prompt hard X-ray
  10. LIGO/Virgo G270580: Swift-XRT sources
  11. LIGO/Virgo G270580: Swift/BAT data search
  12. LIGO/Virgo G268556: Global MASTER Net 21 OTs detection
  13. LIGO/Virgo G270580: Mini-MegaTORTORA follow-up observations
  14. LIGO/Virgo G270580: Pan-STARRS and ATLAS observations of the skymap
  15. LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
  16. LIGO/Virgo G270580: AGILE MCAL and Super-AGILE Observations
  17. LIGO/Virgo G270580 ANTARES search
  18. LIGO/Virgo G270580: Identification of a GW Burst Candidate
  19. LIGO/Virgo G268556: RATIR Observation of iPTF Candidates
  20. LIGO/Virgo G268556: Swift-XRT observations of iPTF17cw
  21. LIGO/Virgo G268556: spectra of two nuclear transients PS17fr and PS17er
  22. LIGO/Virgo G268556: TZAC TAROT network observations with TRE/TCA/TCH
  23. LIGO/Virgo G268556: Gemini spectra of Pan-STARRS1 transients
  24. LIGO/Virgo G268556: Early SWASP limits of ATLAS17aeu
  25. LIGO/Virgo G268556: Additional GROWTH follow up observation of iPTF Optical Transient Candidates
  26. LIGO/Virgo G268556: VLA follow-up of iPTF17cw
  27. LIGO/Virgo G268556/GW170104: Campo Imperatore Observatory observations
  28. LIGO/Virgo G268556: AMI 15 GHz detection of ATLAS17aeu
  29. LIGO/Virgo G268556: Swift/BAT data search
  30. LIGO/Virgo G268556: Lijiang Observatory GMG Telescope Upper Limit on ATLAS17aeu
  31. LIGO/Virgo G268556: Liverpool Telescope Spectroscopy of iPTF17bv and iPTF17ck
  32. LIGO/Virgo G268556: Spectroscopic observations of ATLAS17aeu and iPTF17cw
  33. LIGO/Virgo G268556: NOWT of EWE, Xinglong 0.6/0.9m, Xuyi 1m optical upper limits of ATLAS17aeu and a reminder of GCN 20394
  34. LIGO/Virgo G268556/GW170104: TNG observations of ATLAS17aeu
  35. LIGO/Virgo G268556: Swift-XRT confirms that ATLAS17aeu is fading in X-rays
  36. LIGO/Virgo G268556: ATLAS17aeu position is consistent with GRB170105A
  37. LIGO/Virgo G268556: Liverpool Telescope Spectroscopy of iPTF candidates
  38. LIGO/Virgo G268556: Pan-STARRS1 observations and summary of transient sources
  39. LIGO/Virgo G268556/GW170104: 10.4m GTC spectroscopic observations of iPTF17fs
  40. LIGO/Virgo G268556/GW170104: TNG spectroscopic observations of iPTF17ck and iPTF17dz
  41. LIGO/Virgo G268556: Gemini spectrum and Pan-STARRS observations of ATLAS17aeu
  42. LIGO/Virgo G268556: IPN Triangulation of GRB 170105A (association with ATLAS17aeu)
  43. LIGO/Virgo G268556: GWAC_F60B (60cm) follow-up two events of EWE001 and EWE002
  44. LIGO/Virgo G268556/GW170104: Lomonosov BDRG observations
  45. LIGO/Virgo G268556: Continued iPTF Observations and Additional Optical Transient Candidates
  46. LIGO/Virgo G268556: Swift/UVOT observations of ATLAS17aeu
  47. LIGO/Virgo G268556: CALET Observations
  48. LIGO/Virgo G268556: iPTF Optical Transient Candidates
  49. LIGO/Virgo G268556: VLA follow-up of ATLAS17aeu
  50. LIGO/Virgo G268556: AGILE-GRID preliminary analysis
  51. LIGO/Virgo G268556: EWE001 and EWE002- two events close to GCN 20382 with the skymap
  52. LIGO/Virgo G268556: Palomar 200-inch detects ATLAS17aeu, possible afterglow of GRB070105A?
  53. LIGO/Virgo G268556/GW170104: Global MASTER Net second OT detection
  54. LIGO/Virgo G268556: Swift-XRT detection of ATLAS17aeu
  55. LIGO/Virgo G268556: SWASP optical imaging
  56. LIGO/Virgo G268556/GW170104: Asiago Observations
  57. LIGO/Virgo G268556: Updated sky map from gravitational-wave data
  58. LIGO/Virgo G268556: HAWC follow-up of northern sky
  59. LIGO/Virgo G268556: Pan-STARRS1 observations of the skymap
  60. LIGO/Virgo G268556: ATLAS17aeu - an unusual transient within the skymap
  61. LIGO/Virgo G268556/GW170104: Global MASTER Net observations and first OT detection
  62. LIGO/Virgo G268556: ATLAS imaging of the skymap
  63. LIGO/Virgo G268556: DESGW/DECam observations
  64. LIGO/Virgo G268556: AGILE MCAL and Super-AGILE Observations
  65. LIGO/Virgo G268556: Fermi-LAT search for high-energy gamma-ray counterpart
  66. LIGO/Virgo G268556: Mini-MegaTORTORA follow-up observations
  67. LIGO/Virgo G211117 / GW151226: LOFAR follow-up
  68. LIGO/Virgo G268556: Swift-XRT sources
  69. LIGO/Virgo G268556: ANTARES search
  70. LIGO/Virgo G268556: observation regions by Project Mini-GWAC of SVOM
  71. LIGO/Virgo G268556: INTEGRAL search of temporally coincident prompt hard X-ray emission
  72. LIGO/Virgo G268556: Fermi GBM Observations
  73. LIGO/Virgo G268556: Identification of a GW CBC Candidate
  74. Fermi GBM Observations of IceCube-161103
  75. GRB 160927A: NOT optical observations
  76. IPN Triangulation of GRB 160822A (short/hard)
  77. IPN Triangulation of GRB 160820A (short/hard)
  78. Fermi GBM Observations of IceCube-160806A
  79. LIGO/Virgo G211117 / GW151226: Sky maps and other data available in LOSC
  80. LIGO/Virgo G197392 / LVT151012: Sky maps and other data available in LOSC
  81. LIGO/Virgo G211117/GW151226: serendipitous XMM-Newton slew observations
  82. LIGO/Virgo G211117: Astrosat CZTI upper limits
  83. IceCube-160427A: Fermi GBM Observations
  84. LIGO/Virgo G197392 / LVT151012: Identification of a GW CBC Candidate
  85. LIGO/Virgo G211117: EWE for NOWT of 12 days follow-up of northern sky
  86. LIGO Virgo G211117: Additional MWA Observations
  87. IPN Triangulation of GRB 160406A (short/hard)
  88. LIGO/Virgo G211117: 10.4m GTC follow-up of PS15dpn
  89. LIGO/Virgo G211117: LOFAR follow-up
  90. LIGO/Virgo G211117: CALET GBM Observations
  91. LIGO/Virgo G211117: EWE for NOWT follow-up of northern sky
  92. LIGO/Virgo G194575: EWE for NOWT follow-up of northern sky
  93. LIGO/Virgo G211117: HAWC follow-up of northern sky
  94. LIGO/Virgo G211117: GRAWITA LBT follow-up of PS15dpn
  95. IPN Triangulation of GRB 160225B
  96. IPN Triangulation of GRB 160219A (short/hard)
  97. LIGO/Virgo GW150914
  98. LIGO/Virgo GW150914: BOOTES-3 simultaneous imaging
  99. LIGO/Virgo G184098: MASTER arhival results
  100. LIGO/Virgo G184098: Correction for GCN Circular 18361

Advanced

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