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"

20985 results found.

  1. GRB 170203A: 15 GHz upper limits from AMI
  2. GRB 170202A: 15 GHz upper limits from AMI
  3. GRB 170209A: Swift-XRT observations
  4. GRB 170209A: Swift ToO observations
  5. GRB 170208B: Swift/UVOT Upper Limits
  6. GRB 170208B: RATIR Optical and NIR Observations
  7. GRB 170209A: Fermi GBM Detection
  8. Correction to GCN 20640: GRB 170208B: GROND observations
  9. Fermi Trigger 508295323: MASTER-OAFA possible OT detection
  10. GRB 170208A: Swift/UVOT Upper Limits
  11. GRB 170208B: GROND observations
  12. GRB 170208B: NOT upper limits
  13. GRB 170208B: Etelman observatory optical observations
  14. GRB 170206B: Swift/UVOT Upper Limits
  15. GRB 170206A: POLAR observation
  16. GRB 170205A: Swift/UVOT Detection of a Fading Afterglow
  17. GRB 170205A: NOT afterglow observations
  18. GRB 170205A: RATIR Optical and NIR Observations
  19. GRB 170202A: SMARTS optical/IR afterglow observations
  20. GRB 170205A: LCO FTN observations
  21. GRB 170202A: SQUEAN Observation (2nd night)
  22. GRB 170202A: Zadko observatory - Gingin optical observations
  23. GRB 170202A: Etelman Observatory optical observations
  24. GRB 170202A: RATIR Optical and NIR Observations
  25. GRB 170202A: SQUEAN Observation
  26. GRB 170202A: LCO FTN observations
  27. GRB 170202A: T100 observations
  28. GRB 170202A VLT/X-shooter redshift [minor correction]
  29. GRB 170202A: Swift/UVOT Detection
  30. GRB 170202A: Redshift from OSIRIS/GTC
  31. GRB 170202A: NOT afterglow observations
  32. GRB 170202A: Kanata optical and infrared observations
  33. GRB 170202A: Zadko observatory - Gingin optical observations
  34. GRB 170202A: LCO Sutherland observations
  35. GRB 170202A : Xinglong TNT optical observation
  36. GRB 170131A: Swift/UVOT Upper Limits
  37. GRB 170131A: Swift-XRT observations
  38. GRB 170131A: Swift ToO observations
  39. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  40. GRB 170127C: Swift-XRT observations
  41. GRB 170127A: GROND Upper limits
  42. GRB 170127B: Swift/UVOT Upper Limits
  43. GRB 170127A: Swift/UVOT Upper Limits
  44. GRB 170127C: Tiled Swift observations
  45. LIGO/Virgo G270580: HAWC follow-up observations
  46. GRB 170127B: MASTER-Kislovodsk early optical observations
  47. LIGO/Virgo G270580: Swift/UVOT follow-up of PS17yt
  48. GRB 170126A: Swift/UVOT Detection of a Fading Afterglow
  49. LIGO/Virgo G270580: Fermi GBM Observations
  50. GRB 170115A: 15 GHz upper limits from AMI
  51. LIGO/Virgo G270580: MAXI/GSC observations
  52. LIGO/Virgo G270580: NOT observations of PS17yt
  53. LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
  54. LIGO/Virgo G270580: Asiago 1.82m observations of PS17ua and PS17yt
  55. LIGO/Virgo G270580: 10.4m GTC spectroscopic observations of PS17yt
  56. LIGO/Virgo G270580: Liverpool Telescope classification of EM candidates
  57. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  58. GRB 170121B: AbAO optical observations
  59. LIGO/Virgo G270580: UL50 observations
  60. GRB 170121B: MASTER early optical observations of the Swift possible XT
  61. LIGO/Virgo G270580: CALET Observations
  62. GRB 170121B: Swift-XRT and UVOT observations
  63. LIGO/Virgo G270580/GW170120 : Asiago observations
  64. GRB 170121B: LCO FTN observations
  65. LIGO/Virgo G268556/GW170104: MAXI/GSC observations
  66. GRB 170121B: Swift ToO observations
  67. LIGO/Virgo G270580: ATLAS coverage and 4 optical transients
  68. GRB 170121B/Fermi trigger 506702667 MASTER-Amur OT detection
  69. LIGO/Virgo G270580: Two optical counterpart candidates from CNEOST
  70. LIGO/Virgo G270580: INTEGRAL search of temporally coincident prompt hard X-ray
  71. LIGO/Virgo G270580: Swift-XRT sources
  72. LIGO/Virgo G268556: Global MASTER Net 21 OTs detection
  73. LIGO/Virgo G270580: Mini-MegaTORTORA follow-up observations
  74. LIGO/Virgo G270580: Pan-STARRS and ATLAS observations of the skymap
  75. LIGO/Virgo G270580: Observations of initial skymap by Project Mini-GWAC of SVOM
  76. LIGO/Virgo G270580: AGILE MCAL and Super-AGILE Observations
  77. GRB 170117A: Swift/UVOT Upper Limits
  78. GRB 170117A: Swift-XRT observations
  79. GRB 170117A: Swift ToO observations
  80. GRB 170115A: Swift/UVOT Upper Limits
  81. GRB 170115B: Swift-XRT observations
  82. LIGO/Virgo G268556: Swift-XRT observations of iPTF17cw
  83. GRB 170112A : AbAO optical observations
  84. GRB 170115B: Tiled Swift observations
  85. GRB 170113A: VLT/X-shooter redshift
  86. GRB 170113A: GROND afterglow observations
  87. GRB 170113A: Swift/UVOT Observations
  88. GRB 161214B: 15 GHz upper limits from AMI
  89. GRB 170113A: Fermi GBM observations
  90. GRB 170112A: Swift/UVOT Upper Limits
  91. GRB 170101A: 15 GHz upper limits from AMI
  92. GRB 170113A: LCO Sutherland observations
  93. GRB 161217A: 15 GHz upper limits from AMI
  94. LIGO/Virgo G268556: TZAC TAROT network observations with TRE/TCA/TCH
  95. GRB 170112A: RATIR Optical and NIR Observations
  96. GRB 161219B: afterglow and SN2016jca optical observations
  97. GRB 170111A: Swift/UVOT Upper Limits
  98. GRB 170112A: Swift-XRT observations
  99. GRB 170112A: MASTER-OAFA (Argentina) early optical observations
  100. GRB 170112A: REM optical/NIR 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