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"

28059 results found.

  1. GRB 090509: GROND further analysis and redshift limit
  2. GRB 090509: REM NIR afterglow
  3. GRB 090509: GROND afterglow candidate
  4. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  5. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
  6. GRB 090427: GROND observations
  7. GRB 090429A: ROVOR magnitude limit
  8. ICSP VLF observation of GRB090427 from two receivers
  9. ICSP VLF observation of GRB090424 from four receivers
  10. GRB 090428B: Suzaku WAM observation of the prompt emission
  11. GRB 090424, SMARTS optical/IR afterglow monitoring
  12. GRB 090429D: Fermi GBM detection
  13. GRB 090429C: Fermi GBM detection
  14. GRB 090429B: Swift/UVOT Upper Limits
  15. GRB 090429A: Swift/UVOT Upper Limits
  16. GRB 090429B: Gemini-N further nIR observations
  17. GRB 090429A: Swift-XRT refined analysis
  18. GRB 090429A: GROND upper limits
  19. GRB 090427C: Fermi GBM detection
  20. GRB 090427B: Fermi GBM detection
  21. GRB 090426C: Fermi GBM detection
  22. GRB 090426B: Fermi GBM detection/observation
  23. GRB 090429B: Swift XRT refined analysis
  24. GRB 090429A: Enhanced Swift-XRT position
  25. GRB 090428B: Fermi GBM detection
  26. GRB 090428: Fermi GBM detection
  27. GRB 090418A BVRcIc field calibration
  28. GRB 090429B: RIMOTS optical upper limits
  29. GRB 090429B: Swift-BAT refined analysis
  30. GRB 090429A: Swift-BAT refined analysis
  31. GRB 090429B: Enhanced Swift-XRT position
  32. GRB090429B: Gemini-N infrared IR candidate
  33. GRB 090429B: VLT upper limits
  34. GRB 090429B: GROND Observations
  35. GRB 090429B: Super-LOTIS early observations
  36. GRB 090429B: Swift detection of a burst
  37. GRB 090429: Swift detection of a burst
  38. GRB 090423: pseudo burst at z=1 and its relation to GRB 080913
  39. GRB 090424 : Multiband Optical observation from Nainital
  40. IPN triangulation of very bright GRB 090427
  41. GRB 090423: CARMA mm observations
  42. GRB 090426: Swift/BAT spectral lag results
  43. GRB 090425: Fermi GBM detection
  44. GRB 090424: Suzaku WAM observation of the prompt emission
  45. GRB 090426: VLT spectroscopy
  46. GRB 090426: GROND Observations of the Optical/NIR Afterglow
  47. GRB 090426: Okayama MITSuME optical observation
  48. GRB 090426: Swift-BAT refined analysis
  49. GRB 090426: Swift-XRT refined analysis
  50. GRB 090423: GROND second epoch imaging and refined SED
  51. Detection of bright radio afterglow of GRB 090424 with the VLA
  52. GRB 090426: Enhanced Swift-XRT position
  53. GRB090426: Observation for Optical counterpart from MIRO
  54. GRB 090426, RIMOTS optical upper limits
  55. GRB 090426: Swift detection of a burst with an optical counterpart
  56. GRB 090424: MASTER-Net prompt optical limit
  57. GRB 090424: WHT ISIS spectroscopy
  58. VLA radio observation of high-z GRB 090423
  59. GRB 090424: THO optical observations
  60. GRB 090424: GROND Observations of the Optical/NIR Afterglow
  61. GRB 090423: Y-band field calibration update/correction
  62. GRB 090423: Swift/BAT spectral lag results
  63. GRB 090424 : TAOS optical detection
  64. GRB 090424: Liverpool Telescope observations
  65. GRB 090424: Swift-XRT refined analysis
  66. GRB 090424: Optical observations from 1.23m CAHA
  67. GRB 090423: energetic, luminosity and jet break
  68. GRB 090424: MASTER-Net prompt optical observations
  69. GRB 090424: Enhanced Swift-XRT position
  70. GRB 090424: Swift-BAT refined analysis
  71. GRB 090423: Fermi GBM observation
  72. GRB 090424: Swift detection of a burst with an optical counterpart
  73. GRB090423: Y-band field calibration
  74. GRB 090423 limiting magnitudes
  75. GRB 090423: Near infrared observation at Okayama Observatory
  76. GRB 090423: Deep z-band upper limit and confirmation of photo-z
  77. GRB 090423: GROND detection and preliminary photo-z
  78. GRB 090423: NOT z-band limit
  79. GRB 090423: Swift-XRT refined analysis
  80. GRB090418A Rc-band photometry
  81. GRB 090423: NIR photometry and evidence for spectral break
  82. GRB 090422: Swift-XRT refined analysis
  83. GRB090423, RIMOTS optical upper limits
  84. GRB 090423: Enhanced Swift-XRT position
  85. GRB 090423: Swift-BAT refined analysis
  86. GRB 090422: Swift/UVOT Upper Limits
  87. GRB 090423: UKIRT K-band observations
  88. GRB 090423: P60 Observations
  89. GRB 090418A: R and I band observation
  90. GRB 090423: Swift detection of a burst
  91. GRB 090422: Liverpool Telescope possible candidate
  92. GRB 090418A: Konus-Wind and Swift/BAT joint spectral analysis
  93. GRB 090422: Swift-BAT refined analysis
  94. GRB 090422: Enhanced Swift-XRT position
  95. GRB 090418B: RTT150 optical observations
  96. GRB 080410: GAO 150cm telescope Optical Observation
  97. GRB 080408A: GAO 150cm telescope Optical Observation
  98. GRB 090422: Liverpool Telescope observations
  99. GRB 090418B: Suzaku WAM observation of the prompt emission
  100. GRB 090422: Swift detection of a burst

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