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"

20828 results found.

  1. GRB 130505A: iTelescope T12 optical observations
  2. GRB 130505A: Xinglong TNT optical observations
  3. GRB 130505A; Weihai optical observations
  4. GRB 130504A: IAC80 optical candidate
  5. GRB 130504A: Bassano Bresciano Observatory optical upper limit
  6. GRB 130504A: Swift/UVOT Upper Limits
  7. GRB 130502B: possible TNG counterpart
  8. GRB 130427A: Non-observation of VHE emission with HAWC
  9. GRB130502A: MASTER-Net optical observations
  10. GRB 130502B: Swift/UVOT Upper Limits
  11. GRB 130502A: Swift/UVOT Upper Limits
  12. GRB 130502B: P60 Observations
  13. GRB 130502B Swift-XRT observations
  14. GRB 130502A: RATIR Optical and NIR Observations
  15. GRB 130427A: Pan-STARRS 1 optical observations
  16. GRB 130418A: TNG NIR observations
  17. GRB 130502A: OSN and IAC80 I-band observations
  18. GRB 130502A: z-band observations from GTC
  19. GRB 130502A: TNG candidate counterpart
  20. GRB 130502A: T100 Observations
  21. GRB 130427A: Predictions about the occurrence of a supernova
  22. GRB 130427A: KAIT optical observations
  23. GRB 130427A: SARA-N optical observations
  24. GRB 130427A: VLA 20 GHz detection
  25. GRB 130427A: ABT optical observations
  26. GRB 130427A: GMRT radio detection
  27. GRB 130427A: Continued GMG optical observations
  28. GRB 130427A: Nishi-Harima Optical Spectroscopic Observations
  29. GRB 130427A: Continued RATIR Optical and NIR Observations
  30. GRB 130427A: Challis Observatory optical observations
  31. GRB 130427A: Continued Skynet/PROMPT Observations
  32. GRB 130427A: further GMG observations
  33. GRB 130427A: Continued RATIR Optical and NIR Observations
  34. GRB 130425: MASTER-Net optical observations
  35. GRB 100728A: GROND host detection and X-shooter redshift
  36. GRB 130427A: Skynet/PROMPT Observations
  37. GRB 130427B: RATIR Optical and NIR Observations
  38. GRB 130427A: Nishi-Harima NIR Observations
  39. GRB 130427A: CARMA 3mm observations
  40. GRB 130427A optical time series
  41. GRB 130427A, Optical Observations
  42. GRB 130427A: Continued iTelescope T21 optical observations
  43. Konus-Wind observation of GRB 130427A
  44. GRB 130427A: SPI-ACS/INTEGRAL observations
  45. GRB 130427A: Continued RATIR Optical and NIR Observations
  46. GRB 130427A: CARMA 85 GHz detection
  47. GRB 130427A: SNUO/SOAO/BOAO Observation
  48. GRB 130427A: VLA 5 GHz detection
  49. GRB 130427A: NOT optical photometry and redshift
  50. GRB 130427A: T100 observations
  51. GRB 130427A: optical observations in CrAO
  52. GRB130427A: Swift/UVOT followup observations of an Optical Afterglow
  53. GRB 130427A: Zadko observatory - Gingin optical observations
  54. GRB 130427A: GMG optical observation
  55. GRB 130427A: Optical Observations
  56. GRB 130427A: RATIR Optical and NIR Observations
  57. GRB 130427A: Weihai optical observations
  58. GRB 130427A: iTelescope T11 optical observations
  59. GRB 130427A: Continued P60 follow-up of an extremely bright optical afterglow
  60. GRB 130427A: Gemini-North redshift
  61. GRB 130427A: PAIRITEL NIR Detections
  62. GRB 130427A: Faulkes Telescope North detection
  63. GRB 130427A: P60 early detection
  64. GRB 130427A: early optical observations
  65. GRB 130427A: P60 early nondetection
  66. GRB 130420A: Continued Skynet/GORT Observations/Detections
  67. GRB 130420B: CARMA and VLA radio observations
  68. Trigger 554491: Swift detection of a spike possibly from Sgr A*
  69. GRB 130420A: Continued RATIR Optical and NIR Observations
  70. GRB 130420A: ROTSE-III data analysis
  71. GRB 130420A: Continued RATIR Optical and NIR Observations
  72. GRB 130418A: Continued RATIR Optical and NIR Observations
  73. GRB 130420A: Early RAPTOR Simultaneous Multi-Color Observations
  74. GRB 130418A: WSRT radio observation
  75. GRB 130420B: RATIR Optical and NIR Observations
  76. GRB 130420A: Continued RATIR Optical and NIR Observations
  77. GRB 130420A: ISON-NM optical observations
  78. Skynet/GORT observations of GRB130420A
  79. GRB 130420B: Swift/UVOT Upper Limits
  80. GRB 130420A: Swift/UVOT Detection
  81. GRB130420B: GMG optical upper limit
  82. GRB 130420A: GMG optical observation
  83. GRB 130420B: Faulkes Telescope North observations
  84. GRB 130420A: Weihai Optical Observations
  85. GRB 130420B: MASTER-Net optical observations
  86. GRB 130420A: T21 optical observations
  87. GRB 130420A: RATIR Optical and NIR Observations
  88. GRB 130420A: PAIRITEL NIR detections
  89. GRB 130420A: ROTSE-III Detection of Optical Counterpart
  90. GRB 130418A: Continued RATIR Optical and NIR Observations
  91. GRB 130418A: SMARTS optical/IR afterglow observations
  92. GRB 130418A: Submm observations from SMA
  93. GRB 130327B: Swift/XRT source is not the afterglow
  94. GRB 130419B (Swift trigger Trigger 553930): MASTER-Net optical observations
  95. GRB 130418A: T18 and T21 optical observations
  96. GRB 130418A: LOAO Observation
  97. GRB 130418A, Swift-BAT refined analysis
  98. GRB 130418A: REM NIR observations
  99. GRB 130418A: RATIR Optical and NIR Observations
  100. GRB 130418A: CARMA 3mm detection

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