Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"
  1. GRB 111201A: Swift/UVOT Upper Limits
  2. GRB111201A: Swift-XRT observations
  3. GRB 111201A found in ground analysis of BAT data
  4. GRB 111121A: Suzaku WAM observation of the prompt emission
  5. GRB 111129A: Swift/UVOT Detection
  6. GRB 111129A, GROND afterglow observations
  7. GRB 111129A: Swift-XRT refined Analysis
  8. GRB 111126A Circular #12599 erratum
  9. GRB 111129A: Swift-BAT refined analysis
  10. GRB 111129A: Enhanced Swift-XRT position
  11. GRB 111129A: Swift detection of a burst with an optical counterpart
  12. GRB 111126A found in ground analysis of BAT data
  13. GRB 111123A, Swift-BAT refined analysis
  14. GRB 111123A: Swift/UVOT Upper Limits
  15. GRB 111123A - NOT optical observations
  16. GRB 111123A, GROND observations
  17. GRB 111123A: correction to GCN 12593
  18. GRB 111123A: TNG NIR detection of the afterglow candidate
  19. GRB 111123A: Swift-XRT refined Analysis
  20. GRB 111123A: MITSuME Okayama Optical upper limits
  21. GRB 111123A: Enhanced Swift-XRT position
  22. GRB 111123A: GMG optical observation
  23. GRB 111117A: Refined Chandra Astrometry
  24. GRB 111123A: Swift detection of a burst
  25. GRB 111117A, the review of the sky area in plate archives
  26. Konus-Wind observation of GRB 111121A
  27. GRB 111121A: Swift/UVOT Upper Limits
  28. GRB 111121A: Magellan/Megacam observations
  29. GRB 111121A: Swift-XRT refined Analysis
  30. GRB 111121A: Swift-BAT refined analysis
  31. GRB 111117A: Chandra detection of the afterglow
  32. GRB 111121A: Enhanced Swift-XRT position
  33. GRB 111121A: Swift detection of a short hard burst
  34. GRB 111117A: Gemini Afterglow Limits
  35. GRB 111117A: optical upper limit in CrAO
  36. GRB 111117A: Fermi GBM observation
  37. GRB 111117A: further NOT observations
  38. GRB 111117A: EVLA observations
  39. GRB 111117A: TNG observations
  40. GRB 111117A: Swift/UVOT Upper Limits
  41. GRB 111117A: GROND observations
  42. GRB 111117A: Gemini host observation
  43. GRB111117A: Magellan IMACS observations
  44. GRB 111117A: Swift-XRT refined Analysis
  45. GRB111107A: Further ATCA observations - no detection
  46. GRB 111117A: NOT observations
  47. GRB 111117A: Chandra ToO observation scheduled
  48. GRB 111117A: Swift-BAT refined analysis of a short hard burst
  49. GRB 111117A: GMG upper limit
  50. GRB 111117A: Swift detection of a short hard burst
  51. GRB111107A: ATCA observations - upper limit and a possible detection
  52. Konus-Wind observation of GRB 111113A
  53. IPN Triangulation of GRB 111113A (short/hard/intense)
  54. XRF 111111A/MAXI J0158-744: MAXI GSC refined analysis
  55. XRF 111111A/MAXI J0158-744: MAXI GSC and SSC detection of a soft X-ray transient near SMC
  56. GRB 111109A: Swift-XRT refined Analysis
  57. GRB 111109A: Swift/UVOT Photometry
  58. GRB 111109A: Swift-BAT refined analysis
  59. GRB 111109A: Enhanced Swift-XRT position
  60. GRB 111109A: Swift-XRT observations
  61. GRB 111109A: Swift detection of a burst
  62. GRB 111103B: optical upper limit of CrAO
  63. GRB 111103B: optical upper limit of Mt. Terskol observatory
  64. GRB 111107A: Fermi GBM observation
  65. Continued Skynet observations of GRB111107A
  66. GRB 111107A: Swift-XRT refined Analysis
  67. GRB 111107A: VLT/X-shooter spectroscopy
  68. GRB 111107A: APEX submm observation
  69. GRB 111107A: Swift/UVOT Afterglow Analysis
  70. GRB 111107A: Swift-BAT refined analysis
  71. GRB 111107A: Enhanced Swift-XRT position
  72. GRB 111107A: Gemini-South Redshift
  73. GRB 111107A: GROND observations
  74. Skynet observations of GRB 111107A
  75. GRB 111107A: Swift detection of a burst with an optical counterpart
  76. GRB 111103B: MITSuME Akeno Optical upper limits
  77. Konus-Wind observation of GRB 111103B
  78. GRB 111103B : WIYN 3.5m NIR observations
  79. GRB 111103B: Swift-XRT refined Analysis
  80. GRB 111103A: Fermi GBM observation
  81. GRB111103B Swift/UVOT Upper Limits
  82. GRB 111103B: optical observations from TAU, Ka-Dar
  83. Trigger 506913: MASTER detection of Swift J1922.7-1716 optical counterpart
  84. GRB 111103B: Enhanced Swift-XRT position
  85. GRB 111103B: Swift-BAT refined analysis
  86. GRB 111103A: Swift-BAT refined analysis
  87. Trigger 506913: Swift detection of Swift J1922.7-1716 and its optical counterpart
  88. GRB 111022B: MASTER OT observations
  89. GRB 111103B: optical observations
  90. GRB 111103B: Swift detection of a strong burst from a GRB or Galactic source
  91. GRB 111103A: Swift detection of a burst
  92. Swift-BAT trigger 506884 is not a GRB
  93. GRB 111029A: RAPTOR Limits During the Gamma-ray Emitting Interval
  94. GRB 111029A: SAO RAS optical limits
  95. GRB 111029A: Super-LOTIS early limits
  96. All GCN Circulars available in a tarfile for data mining
  97. GRB 111026A: spectral lag value inconclusive for a short burst
  98. GRB111029A: MITSuME Ishigakijima Optical Upper Limits
  99. GRB 111029A: TNT optical upper limit, Correction to GCN 12503
  100. GRB 111029A: Swift-XRT refined Analysis

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