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"

19565 results found.

  1. LIGO/Virgo G184098: MWA Followup
  2. LIGO/Virgo G184098: DESGW followup program
  3. LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
  4. LIGO/Virgo G184098: Fermi-GBM ground-based follow-up
  5. LIGO/Virgo G184098: Observations from the TOROS collaboration
  6. LIGO/Virgo G184098: observations by MASTER
  7. LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
  8. LIGO/Virgo G184098: Swift follow-up observations
  9. LIGO/Virgo G184098: Burst candidate in LIGO engineering run data
  10. GRB 150915A: Swift-XRT refined Analysis
  11. GRB 150910A: AAO optical observations
  12. GRB150915A : IRSF NIR upper limits
  13. GRB 150915A: NOT observations of a brightening afterglow
  14. GRB 150915A: Swift UVOT upper limits
  15. GRB 150910A: Mt. Terskol observatory optical observations
  16. GRB 150910A: TSHAO optical observations
  17. GRB 150915A: GROND detection of an optical counterpart candidate
  18. GRB 150915A: Swift detection of a burst
  19. GRB 150910A: T100 observations
  20. GRB 150911A: GROND Upper Limits
  21. GRB 150910A: Continued RATIR Observations
  22. GRB 150907A: Swift-XRT afterglow detection
  23. GRB 150912A: Swift-XRT and UVOT observations
  24. GRB 150911A: Chuguev observatory upper limit
  25. GRB 150911A: Mt. Terskol observatory upper limit
  26. GRB 150911A: Khureltogot upper limit
  27. GRB 150910A: Mt. Terskol observatory optical observation
  28. GRB 150912A: MITSuME Ishigakijima upper limits
  29. GRB 150910A: RATIR Observations
  30. GRB 150910A: MITSuME Ishigakijima Optical Observation after 2 days
  31. GRB 150912A: Swift ToO observations
  32. GRB 150911A: Swift/UVOT Upper Limits
  33. GRB 150910A: AAO optical observations
  34. GRB 150910A: MITSuME Ishigakijima Optical Observation after 1 day
  35. GRB 150910A: Chuguev observatory optical observations
  36. GRB 150911A: MITSuME Okayama upper limits
  37. GRB 150910A: continued SAO RAS optical observations
  38. GRB 150911A: Enhanced Swift-XRT position
  39. GRB150911A MITSuME Okayama Ks-band upper-limit
  40. GRB 150910A: TSHAO optical observations
  41. GRB 150911A: Swift detection of a burst
  42. GRB 150910A: NOT observations of the afterglow
  43. GRB 150910A: MITSuME Okayama Ks-band Observation
  44. GRB 150910A: GROND observation of the afterglow
  45. GRB 150910A: MITSuME Ishigakijima Optical Observation
  46. GRB 150910A: SAO RAS optical photometry
  47. GRB 150910A: Enhanced Swift-XRT position
  48. GRB 150910A: Swift/UVOT Detection of a Brightening Afterglow
  49. GRB 150910A: Nanshan optical observations
  50. GRB 150910A: MITSuME Okayama Optical Observation
  51. GRB 150910A: Swift detection of a burst with an optical afterglow
  52. Fermi GBM trigger 463422723/150908689 is not a GRB
  53. IPN Triangulation of GRB 150906B (short/intense)
  54. GRB150907A: Swift/UVOT observations
  55. GRB 150907B: Enhanced Swift-XRT position
  56. GRB 150907B: GROND Upper Limits
  57. GRB 150907B: Swift-XRT observations
  58. GRB 150907A: Tiled Swift observations
  59. GRB 150906A: Fermi GBM detection
  60. GRB 150818A: TSHAO and SAO RAS optical observations
  61. GRB 150902A: Swift-XRT afterglow detection
  62. ANTARES neutrino detection: ANU 2.3m and Kepler K2 Observations of the Swift x-ray source
  63. GRB 150902A: Swift/UVOT Upper Limits
  64. GRB 150831A: 9.8 GHz VLA upper limits
  65. GRB 150902A: Swift ToO observations
  66. GRB 150831B: Swift/UVOT Upper Limits
  67. GRB 150831B: Swift-BAT refined analysis
  68. GRB 150831A: GROND Upper Limits
  69. GRB 150831A: Swift/UVOT Upper Limits
  70. GRB 150831B: Swift-XRT observations
  71. GRB 150831A: Swift-XRT refined Analysis
  72. GRB 150831A: Swift-BAT refined analysis
  73. GRB 150831A: Enhanced Swift-XRT position
  74. GRB 150831A: optical upper limit ISON-SSO
  75. GRB 150831A: Swift detection of a short burst
  76. GRB 150821A, Swift-BAT refined analysis
  77. GRB 150821A: GROND afterglow observations
  78. GRB 150821A: Swift-XRT refined Analysis
  79. GRB 150819A: Mondy and TSHAO optical upper limits
  80. GRB 150821A: Swift/UVOT Detection
  81. GRB 150821A: Enhanced Swift-XRT position
  82. GRB 150821A: Swift detection of a burst with an optical afterglow
  83. GRB150819A: NOT imaging
  84. GRB 150818A: Continued NOT monitoring - afterglow confirmation
  85. GRB 150818A: Mondy optical observations
  86. GRB 150818A: MITSuME Ishigakijima upper limits
  87. GRB 150819A: RATIR Optical Observations
  88. GRB 150819A: Swift-BAT refined analysis
  89. GRB 150819A: Swift/UVOT Upper Limits
  90. GRB 150819A: Enhanced Swift-XRT position
  91. GRB150818A: NOT imaging
  92. GRB 150819A: Swift detection of a burst
  93. GRB 150818A: Swift/UVOT Detection
  94. GRB 150817A: AAO optical observations
  95. GRB 150818A: Enhanced Swift-XRT position
  96. GRB 150817A: Continued RATIR Optical Observations - Afterglow Confirmation
  97. GRB 150818A: Swift detection of a burst
  98. GRB 150817A: Swift/UVOT Upper Limits
  99. GRB 150817A: Enhanced Swift-XRT position
  100. GRB 150817A: Continued RATIR Observations, Revised Candidate

Advanced

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