Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
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"
  1. GRB 110520A: Liverpool Telescope Observations
  2. GRB 110520A: TAROT Calern observatory optical observations
  3. GRB 110520A: MASTER-NET optical observations
  4. GRB 110520A: Swift detection of a burst
  5. Konus-Wind observation of GRB 110518A
  6. IPN localization of bright GRB 110518A
  7. Radio observations of GRB 110428A with the EVLA
  8. GRB 110519A, Swift-BAT refined analysis
  9. GRB 110519A: Swift detection of a burst
  10. GRB 110503A optical observation
  11. GRB 110426A: Fermi GBM detection
  12. GRB 110428A: Fermi-GBM observation
  13. GRB 110503A: TAROT Calern observatory optical observations
  14. GRB 110503A: Jet Break seen from TLS
  15. GRB 110503A optical observations
  16. Konus-Wind observation of GRB 110503A
  17. GRB 110422A: MASTER first 30 min OT light curve
  18. GRB 110422A: Herschel FIR observation preliminary report
  19. GRB 110503A: optical observation in CrAO
  20. GRB 110503A: R-band Detection
  21. GRB 110503A: Centimeter observation from EVLA
  22. GRB 110503A: Millimeter observation from SMA
  23. GRB 110503A: SARA-N Observations and Photometric Calibration
  24. GRB 110503A: Swift/UVOT Observations
  25. GRB 110503A: Swift-XRT refined Analysis
  26. GRB 110503A: PAIRITEL NIR Detection
  27. GRB 110503A: redshift confirmation from TNG
  28. GRB 110503A - TLS Afterglow Observations
  29. GRB 110503A: Swift-BAT refined analysis
  30. GRB 110503A: NOT afterglow photometry
  31. GRB 110503A: Redshift from 10.4m GTC
  32. GRB 110503A: Enhanced Swift-XRT position
  33. GRB 110503A: Swift detection of a burst with a bright optical counterpart
  34. GRB 110426A: Swift/XRT non-detection
  35. GRB 110428A : X-ray afterglow confirmation
  36. GRB 110428A: Suzaku WAM observation of the prompt emission
  37. Fermi-GBM data processing and delivery
  38. GRB 110422A: optical observations in CrAO
  39. GRB 110422A: Update of Herschel FIR observation schedule
  40. GRB 110428A : Swift-XRT observations
  41. Konus-Wind observation of GRB 110428A
  42. GRB 110428A: Fermi-LAT Detection
  43. GRB 110426A: MASTER synchronous with MAXI/GSC observations
  44. GRB 110426A: MAXI/GSC detection of a GRB
  45. GRB 110422A: optical observations in CrAO, second epoch
  46. GRB 110422A: Redshift confirmation from GTC
  47. GRB 110422A: tentative redshift from TNG
  48. GRB 110422A: Suzaku WAM observation of the prompt emission
  49. GRB 110422A: Herschel observation scheduled
  50. GRB110422A: NOT optical follow-ups
  51. GRB 110422A: optical observations in CrAO
  52. GRB110422A: MITSuME Ishigakijima Optical Observation
  53. Konus-Wind observation of GRB 110422A
  54. GRB 110422A: Further NOT observation
  55. GRB 110422A: Swift/UVOT Detection of optical afterglow
  56. GRB 110422A: Swift-XRT refined Analysis
  57. GRB 110422A: CQUEAN griz Observation
  58. GRB 110422A: THO optical observations
  59. GRB 110422A: Enhanced Swift-XRT position
  60. GRB 110422A: correction to the GCN circ. 11958
  61. GRB 110422A: TNG optical observations
  62. GRB 110422A: SAO RAS optical observations
  63. GRB 110422A: NOT optical observation
  64. GRB 110422A: MASTER earlier OT polarization observations
  65. GRB 110422A: Swift-BAT refined analysis
  66. GRB 110422A: Mondy optical observations
  67. GRB 110422A: Swift detection of a burst
  68. GRB 110328A/Swift J164449.3+573451: Maidanak Optical Observation
  69. GRB 110420B: Swift/UVOT Upper Limits
  70. GRB110420A: GROND detection of the Optical/NIR Afterglow Candidate
  71. GRB 110420B: Swift-XRT afterglow candidate retraction
  72. GRB 110420B: Fermi GBM observation
  73. Konus-Wind observation of GRB 110420A
  74. GRB 110420B: Spectral lag indicates short hard burst
  75. GRB 110420B, GROND observations
  76. GRB 110420A Swift/UVOT Observations
  77. GRB 110420B: Swift-XRT afterglow candidate
  78. GRB 110420B: Swift-BAT refined analysis
  79. GRB 110420A: Swift-BAT refined analysis
  80. GRB 110420B: Swift detection of a short hard burst
  81. GRB 110420A: Swift-XRT refined Analysis
  82. GRB 110420A: Enhanced Swift-XRT position
  83. GRB 110420A: Swift detection of a burst with optical counterpart
  84. GRB110414A: MITSuME Ishigakijima Optical upper limits
  85. GRB 110414A: GROND upper limits
  86. GRB110414A: MITSuME Okayama Optical upper limits
  87. GRB 110414A: Swift-BAT Refined Analysis
  88. GRB 110414A: Swift/UVOT Upper limits
  89. GRB 110414A: Swift-XRT refined Analysis
  90. GRB 110414A: Enhanced Swift-XRT position
  91. GRB 110328A / Swift J164449.3+573451: WISE quiescent source upper limit
  92. GRB 110414A : Faulkes Telescope North observations
  93. GRB 110414A: Swift detection of a burst
  94. GRB 110411A: PAIRITEL NIR Upper Limits
  95. GRB 110412A: Swift-BAT refined analysis
  96. GRB 110411A: optical limits from OSN
  97. GRB 110411A: Swift-XRT refined Analysis
  98. GRB 110412A: Fermi GBM observation
  99. GRB 110411A: Swift/UVOT Upper Limits
  100. GRB 110411A: MASTER prompt and follow-up optical limits

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