Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"

675 results found.

  1. GRB 170306A: GROND observations
  2. GRB 170214A: GROND detection in all bands
  3. GRB 170209A: GROND confirmation of MASTER afterglow
  4. GRB 170208B: Swift/UVOT Upper Limits
  5. GRB 170208B: RATIR Optical and NIR Observations
  6. Correction to GCN 20640: GRB 170208B: GROND observations
  7. GRB 170208B WHT nIR candidate afterglow
  8. GRB 170208B: GROND observations
  9. GRB 170127A: GROND Upper limits
  10. GRB 170113A: GROND afterglow observations
  11. GRB 161220A: GROND Upper Limits
  12. GRB 161219B: GROND afterglow observations
  13. GRB 161214A: GROND afterglow observations
  14. GRB 161104A: Magellan imaging and spectroscopy
  15. GRB 161104A: Gemini South optical observations
  16. GRB 161104A: GROND observations
  17. GRB 161023A: GROND Observations
  18. GRB 161001A: MASTER-OAFA and MASTER-SAAO early optical observations
  19. GRB 161001A: GROND afterglow candidate
  20. GRB 160927A: NOT optical observations
  21. GRB 160927A: GROND Observations
  22. GRB 160804A: GROND observations
  23. GRB 160712A: Further GROND observations
  24. GRB 160712A: RATIR Optical and NIR Observations
  25. GRB 160712A: GROND observations
  26. GRB 160625A: GROND upper limits
  27. GRB 160630A: GROND Afterglow Detection
  28. GROND observations of GRB 160622A/SNR RCW 103/SGR 1617-5103
  29. GRB 160607A: GROND confirmation of the afterglow
  30. GRB 160506A: GROND upper limits
  31. GRB 160501A: GROND Upper limits
  32. GRB 160425A: Swift/UVOT Detection
  33. GRB 160422A: GROND NIR afterglow detection
  34. GRB 160425A MASTER notices: possible host galaxy in the optical error-box
  35. GRB 160425A: GROND observation
  36. GRB 160412A: GROND upper limits
  37. GRB 160411A: GROND Optical/NIR upper limits
  38. GRB 160410A: Swift/UVOT Detection
  39. GRB 160410A: GROND optical detection
  40. GRB 160325A: GROND Upper Limits
  41. GRB 160314A: Continued RATIR Optical and NIR Observations
  42. GRB 160314A: GROND optical/NIR observations
  43. GRB 160228A: GROND afterglow confirmation and X-shooter host candidate redshift
  44. GRB 160303A: Continued optical monitoring from NOT
  45. GRB160303A: further GROND observations
  46. GRB 160303A: Continued RATIR Optical and NIR Observations
  47. GRB 160303A: GROND Optical Detection
  48. GRB 160228A: Swift/UVOT Upper Limits
  49. GRB 160228A: RATIR Optical and NIR Observations
  50. GRB 160228A: MASTER-Amur prompt observations
  51. GRB 160228A: GROND Afterglow Candidate
  52. GRB 160223A: Swift-XRT afterglow detection
  53. GRB 160223A: GROND optical/NIR afterglow
  54. GRB 160221A: GROND upper limits
  55. GRB 160220B: Further GROND Observations
  56. Further Swift/UVOT observations of GRB 160220B
  57. GRB 160220B: GROND Observations
  58. GRB 160220A: GROND Optical/NIR Upper Limits
  59. GRB 160206A: GROND Observations
  60. GRB 160203A: GROND Afterglow Candidate
  61. GRB 160131A: GROND Detection of the Optical/NIR Afterglow
  62. GRB 160123A: GROND Upper limits
  63. GRB 160121A: RATIR Optical Observations
  64. GRB 160121A: GROND Afterglow observations
  65. GRB 160117B: further RATIR observations
  66. GRB 160119A: GROND optical/NIR afterglow observations
  67. GRB 160117B: GROND optical/NIR afterglow observations
  68. GRB151215A: Swift/UVOT detection
  69. GRB 151215A: GROND Detection of the Optical/NIR Afterglow
  70. GRB 151212A: GROND Optical Afterglow Candidate
  71. GRB 151210A: GROND Afterglow Confirmation
  72. GRB 151205B: Deep GROND Upper limits
  73. GRB 151205A: Garching Telescope Upper Limit
  74. GRB 151127A: GROND K-band upper limit
  75. GRB 151120A: Swift-XRT afterglow detection
  76. GRB 151120A: GROND optical/NIR afterglow
  77. GRB 151114A: GROND Detection of the Optical/NIR Afterglow Candidate
  78. GRB 151112A: GROND photometric redshift and i'-band prediction
  79. GRB 151111A: GROND confirmation of the afterglow and photometric redshift estimate
  80. GRB 151112A: Swift/UVOT Upper Limits
  81. GRB 151112A: GROND Detection of the Optical/NIR Afterglow Candidate
  82. GRB 151111A: GROND marginal detection of a afterglow candidate
  83. GRB 151031A: GROND observation
  84. GRB 151029A: GROND afterglow observations
  85. GRB 151027B: GROND Optical/NIR Afterglow Detection
  86. LIGO/Virgo G194575: GROND multi-color observations
  87. GRB 151023A: RATIR Observations
  88. GRB 151023A
  89. GRB 150915A: NOT observations of a brightening afterglow
  90. GRB 150915A: Swift UVOT upper limits
  91. GRB 150915A: GROND detection of an optical counterpart candidate
  92. GRB 150911A: GROND Upper Limits
  93. GRB 150910A: NOT observations of the afterglow
  94. GRB 150910A: GROND observation of the afterglow
  95. GRB 150907B: GROND Upper Limits
  96. GRB 150831A: GROND Upper Limits
  97. GRB 150821A: GROND afterglow observations
  98. GRB 150514A: GROND Bright Afterglow Confirmation
  99. GRB 150430A: GROND Upper Limits
  100. GRB 150428A: Danish1.56m optical observations

Advanced

Download all Circulars as a .tar.gz archive:
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