Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. See news and announcements

GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

16156 results found.

  1. LIGO/Virgo G274296: iPTF Optical Transient Candidates
  2. LIGO/Virgo G274296: Kanata 1.5m optical spectroscopy of MASTER optical transient
  3. LIGO/Virgo G274296: Global MASTER Net PSN and QSO detection
  4. LIGO/Virgo G274296: Asiago 1.82m Optical Observations
  5. LIGO/Virgo G274296: MASTER new bright possible SN detection and inspection dinamic
  6. LIGO/Virgo G274296: Optical Observation
  7. LIGO/Virgo G274296: CNEOST imaging coverage and an optical transient
  8. LIGO/Virgo G274296: SWASP optical imaging coverage
  9. LIGO/Virgo G274296: REM optical/NIR observations
  10. GRB 170214A: Mondy optical upper limit
  11. GRB 170214A: VLT/X-shooter spectroscopy and tentative redshift
  12. GRB170214A: RATIR Optical and NIR Afterglow Confirmation
  13. GRB 170214A: GROND detection in all bands
  14. GRB 170214A: NOT optical afterglow confirmation
  15. GRB 170214A: Swift/UVOT Upper Limits
  16. GRB170214A: RATIR Optical and NIR Observations
  17. GRB 170209A: GROND confirmation of MASTER afterglow
  18. GRB 170208B: SMARTS optical/IR observations
  19. GRB 170208B: Swift/UVOT Upper Limits
  20. IPN Triangulation of GRB 170209A
  21. GRB 170208B: RATIR Optical and NIR Observations
  22. Fermi Trigger 508295323: MASTER-OAFA possible OT detection
  23. GRB 170208B WHT nIR candidate afterglow
  24. GRB 170208A: Swift/UVOT Upper Limits
  25. GRB 170208B: GROND observations
  26. GRB 170208B: NOT upper limits
  27. GRB 170208B: Etelman observatory optical observations
  28. LIGO/Virgo G270580: Gemini-South Spectroscopic Classification of Optical Transients
  29. GRB 170206B: Swift/UVOT Upper Limits
  30. GRB 170205A: NOT afterglow observations
  31. GRB 170205A: RATIR Optical and NIR Observations
  32. GRB 170202A: SMARTS optical/IR afterglow observations
  33. GRB 170205A: LCO FTN observations
  34. GRB 170205A: Swift detection of a burst with an optical counterpart
  35. GRB 170202A: Zadko observatory - Gingin optical observations
  36. GRB 170202A: Etelman Observatory optical observations
  37. GRB 170202A: RATIR Optical and NIR Observations
  38. GRB 170202A: LCO FTN observations
  39. GRB 170202A VLT/X-shooter redshift [minor correction]
  40. GRB 170202A: Xinglong 2.16m photometry and spectroscopic redshift
  41. GRB 170202A: MITSuME Akeno Optical Observation
  42. GRB 170202A: NOT afterglow observations
  43. GRB 170202A: Kanata optical and infrared observations
  44. GRB 170202A: Zadko observatory - Gingin optical observations
  45. GRB 170202A: LCO Sutherland observations
  46. GRB 170202A: MASTGlobal ER-Net bright OT nonmonotonic light curve
  47. GRB 170202A: Mini-MegaTORTORA upper limits
  48. GRB 170202A : Xinglong TNT optical observation
  49. GRB 170202A: Swift detection of a burst with an optical afterglow
  50. GRB 170131A: Swift/UVOT Upper Limits
  51. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  52. GRB 170127B: Swift/UVOT Upper Limits
  53. GRB 170127A: Swift/UVOT Upper Limits
  54. GRB 170127B: NOT r-band upper limits
  55. GRB 170127B: MASTER-Kislovodsk early optical observations
  56. GRB 170126A: Swift detection of a burst with an optical counterpart
  57. LIGO/Virgo G270580: NOT observations of PS17yt
  58. LIGO/Virgo G270580: 10.4m GTC spectroscopic observations of PS17yt
  59. LIGO/Virgo G270580: Pan-STARRS coverage and 124 optical transients
  60. GRB 170121B: AbAO optical observations
  61. GRB 170121B: MASTER early optical observations of the Swift possible XT
  62. GRB 170121B: Swift-XRT and UVOT observations
  63. GRB 170121B: LCO FTN observations
  64. LIGO/Virgo G270580: A third optical transient from CNEOST
  65. GRB 170121B: Fermi GBM detection
  66. LIGO/Virgo G270580: ATLAS coverage and 4 optical transients
  67. LIGO/Virgo G270580: Two optical counterpart candidates from CNEOST
  68. LIGO/Virgo G270580: Mini-MegaTORTORA follow-up observations
  69. LIGO/Virgo G270580: Pan-STARRS and ATLAS observations of the skymap
  70. GRB 170117A: Swift/UVOT Upper Limits
  71. GRB 170115A : AbAO optical upper limit
  72. GRB 170115A: Swift/UVOT Upper Limits
  73. GRB 170112A : AbAO optical observations
  74. GRB 170113A: VLT/X-shooter redshift
  75. GRB 170113A: GROND afterglow observations
  76. GRB 170112A: Swift/UVOT Upper Limits
  77. GRB 170113A: LCO Sutherland observations
  78. GRB 170113A: Swift detection of a burst with an optical counterpart
  79. GRB 170112A: RATIR Optical and NIR Observations
  80. GRB 161219B: afterglow and SN2016jca optical observations
  81. GRB 170111A: Swift/UVOT Upper Limits
  82. GRB 170112A: MASTER-OAFA (Argentina) early optical observations
  83. GRB 170112A: REM optical/NIR observations
  84. GRB170111A: REM optical/NIR observations
  85. LIGO/Virgo G268556: Early SWASP limits of ATLAS17aeu
  86. GRB 170111A: SMARTS optical/IR observations
  87. LIGO/Virgo G268556: Additional GROWTH follow up observation of iPTF Optical Transient Candidates
  88. GRB 170111A: MASTER-OAFA (Argentina) prompt OT observations
  89. LIGO/Virgo G268556: AMI 15 GHz detection of ATLAS17aeu
  90. LIGO/Virgo G268556: Lijiang Observatory GMG Telescope Upper Limit on ATLAS17aeu
  91. LIGO/Virgo G268556: NOWT of EWE, Xinglong 0.6/0.9m, Xuyi 1m optical upper limits of ATLAS17aeu and a reminder of GCN 20394
  92. LIGO/Virgo G268556/GW170104: 10.4m GTC spectroscopic observations of iPTF17fs
  93. LIGO/Virgo G268556/GW170104: TNG spectroscopic observations of iPTF17ck and iPTF17dz
  94. LIGO/Virgo G268556: IPN Triangulation of GRB 170105A (association with ATLAS17aeu)
  95. LIGO/Virgo G268556: Continued iPTF Observations and Additional Optical Transient Candidates
  96. LIGO/Virgo G268556: Swift/UVOT observations of ATLAS17aeu
  97. LIGO/Virgo G268556: iPTF Optical Transient Candidates
  98. Discovery Channel Telescope Imaging of ATLAS17aeu (LVCG268556)
  99. LIGO/Virgo G268556: VLA follow-up of ATLAS17aeu
  100. LIGO/Virgo G268556: SWASP optical imaging

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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