Skip to main content
Due to the lapse in federal government funding, NASA is not updating this website. See the Operations FAQ for GCN impacts.
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

2852 results found.

  1. GRB 130427B: MITSuME Ishigakijima upper limits
  2. GRB 130427A: Nishi-Harima NIR Observations
  3. GRB 130427A: T100 observations
  4. GRB 130427A: Swift-BAT refined analysis
  5. GRB 130427A: Optical Observations
  6. GRB 130427A: MAXI/GSC detection
  7. GRB 130427A: Swift detection of a very bright burst with a likely bright optical counterpart
  8. GRB 130420A: Redshift from 10.4m GTC
  9. GRB 130327A: Gemini Observations
  10. GRB 130327A: ISON-NM optical upper limit
  11. GRB 130327A: Enhanced Swift-XRT position
  12. GRB 130327A: Swift detection of a burst
  13. GRB 130325A: Fermi GBM detection
  14. GRB 130315A, Swift-BAT refined analysis
  15. GRB 130305A: Gemini-North upper limit
  16. GRB 121128A: optical observations in Mondy observatory
  17. GRB 130211A: Swift-XRT refined Analysis
  18. GRB 130211A: GROND detection of the afterglow
  19. GRB 130206A: GROND Observations
  20. GRB 130102B: MAXI/GSC detection
  21. GRB 121201A: Swift/UVOT Detection
  22. GRB 121201A: a GRB with an optical counterpart
  23. GRB 121108A: MITSuME Ishigakijima upper limits
  24. GRB 121027A - Gemini South spectroscopy
  25. GRB 121011A: MASTER-Net bell light curve
  26. Trigger 535733: Swift possible detection of SAX J1828.5-1037
  27. IPN Triangulation of long GRB 120919B
  28. IPN Triangulation of long GRB 120919A
  29. Swift Trigger 534017 is probably not real.
  30. IPN Triangulation of long GRB 120916A
  31. GRB 120913A: Swift-BAT refined analysis
  32. GRB 120911A: optical upper limit ISON-NM
  33. IPN Triangulation of GRB 120911B (long/bright)
  34. GRB 120908A: MAXI/GSC detection
  35. GRB 120909A: Swift detection of a burst
  36. GRB 120830A: Swift-XRT and UVOT observations
  37. GRB 120817A: FTN and FTS observations
  38. GRB 120817A: Swift detection of a burst
  39. GRB 120811A: Swift/XRT-UVOT Obseravations
  40. Improved IPN error box for short hard GRB 120811B
  41. GRB 120803A: Swift detection of a possible burst
  42. GRB 120802A: MASTER optical observations
  43. Trigger 529076: Swift possible detection of SwJ1910.2-0546
  44. GRB 120724A: FTN optical afterglow candidate
  45. GRB 120712A: Fermi GBM observation
  46. GRB 120712A: Swift detection of a burst with optical afterglow
  47. GRB 120709A: optical afterglow limits
  48. GRB 120703A: NOT optical observation
  49. GRB 120630A: Swift-BAT/-XRT/-UVOT refined analysis
  50. Watcher follow-up observations of IGR J17062-6143 (Swift trigger 525148)
  51. Skynet/PROMPT observations of IGR J17062-6143 (Swift trigger 525148)
  52. Swift detection of IGR J17062-6143
  53. GRB 120622A: MAXI/GSC detection
  54. GRB 120528B: MAXI/GSC detection
  55. GRB 120521C: EVLA Localization of Afterglow
  56. GRB 120521C: Early Tautenburg limits
  57. GRB 120521A: Swift detection of a short burst
  58. GRB 120510A: MAXI/GSC detection of a burst
  59. GRB 120422A: Additional Gemini observations and Keck/LRIS spectroscopy
  60. GRB 120404A: optical observations in Mondy observatory
  61. GRB 120404A: MITSuME Okayama Optical Observation
  62. Konus-Wind observation of GRB 120323A
  63. GRB 120324A: Liverpool Telescope optical candidate
  64. GRB 120320A , optical observations
  65. IPN Triangulation of GRB 120316A
  66. GRB 120308A: Swift detection of a burst
  67. Konus-Wind observation of GRB 120226A
  68. GRB 120215A: MITSuME Okayama Optical upper limits
  69. Skynet/PROMPT observations of GRB120215A
  70. GRB 120212A: MITSuME Ishigakijima Optical Observation
  71. GRB 120211A: Swift-BAT refined analysis
  72. GRB 120119A: GRT detection of early afterglow
  73. GRB 120121A: Swift detection of a burst
  74. GRB 120102A, the review of the sky area in plate archive
  75. AXP 4U 1042+61: Mondy optical observations
  76. INTEGRAL Weak trigger #6433: GRT Optical Observation
  77. GRB 120106A: Swift detection of a burst
  78. GRB 120102A: Swift-BAT refined analysis
  79. GRB 120102A: Swift/UVOT Detection
  80. GRB 120102A: Enhanced Swift-XRT position
  81. GRB 120102A: Swift detection of a burst with an optical counterpart
  82. GRB 111229A: Swift/UVOT Detection
  83. GRB 111229A: Enhanced Swift-XRT position
  84. GRB 111229A: GROND afterglow candidate
  85. GRB 111229A: Swift detection of a burst
  86. GRB 111228A, Swift-BAT refined analysis
  87. GRB 111103B: optical upper limit
  88. GRB 111209A: IRTF NIR Imaging/Spectroscopy
  89. GRB 111129A: Swift/UVOT Detection
  90. GRB 111129A: Enhanced Swift-XRT position
  91. GRB 111129A: Swift detection of a burst with an optical counterpart
  92. GRB 111126A found in ground analysis of BAT data
  93. GRB 111107A: Swift-XRT refined Analysis
  94. GRB 111103B: optical observations
  95. GRB 111024A: MAXI/GSC detection of a burst
  96. EVLA 22 GHz Detection of GRB 111008A
  97. GRB 111008A: Gemini spectroscopic redshift
  98. GRB 111008A, GROND observations
  99. GRB 111008A: Gemini optical counterpart
  100. GRB 111008A: Enhanced Swift-XRT position

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