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. GRB000604, optical observations, comparison with DPOSS
  2. GRB000604 [IPN Position]
  3. GRB000528, Radio Observations
  4. X-ray Afterglow of GRB 000529
  5. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  6. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  7. GRB000529: Optical Observations
  8. IPN localization and time history of GRB000528
  9. New IPN localization of GRB000529
  10. GRB000519: Optical observations
  11. IPN localization of GRB000529
  12. GRB 000528 - WFC measurements
  13. GRB000529: BeppoSAX WFC position
  14. GRB000528: BeppoSAX GRBM observations
  15. GRB 000528 Optical Observations
  16. GRB000519, BVRI field photometry
  17. IPN triangulation of GRB000519
  18. IPN triangulation of GRB000516
  19. Re: GRB000508B : Optical observations
  20. GRB 000418, Optical observation
  21. GRB000508B, optical photometry
  22. GRB000508B, BVR field photometry
  23. Possible GRB-related phenomenon
  24. RXTE/ASM and IPN localization of GRB 000508B
  25. GRB000424, UBVRI field photometry
  26. GRB 000424 Optical Observations
  27. GRB000418, UBVRI field photometry update
  28. The redshift of GRB 000418
  29. GRB000424, optical observations
  30. GRB 000429, optical observation
  31. GRB 000429, UBVRI field photometry
  32. IPN localization of GRB000429
  33. GRB 000418, UBVRI field photometry
  34. GRB000418, Radio detection
  35. GRB000418, K'-band photometry
  36. GRB 000418, Optical Observation
  37. GRB 000418, optical observation
  38. GRB000424 Optical Observations
  39. GRB 000418, Optical Observation
  40. GRB000424, optical observations
  41. GRB000424, optical observations
  42. GRB 000424, Optical Observations
  43. GRB 000418, Optical Observation
  44. GRB000418, near-infrared observations
  45. BeppoSAX GRB000424
  46. Correction to IPN error box for GRB000419
  47. IPN error box for GRB000418
  48. GRB000419 [IPN Position]
  49. GRB000416 Optical Observations
  50. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  51. GRB000416 BRJK observations
  52. 1SAXJ1715.0-7134 refined position
  53. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  54. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  55. Budget cuts in BeppoSAX operations: impact on GRB observations
  56. GRB 000408, optical observations
  57. Refined IPN error box for GRB000408
  58. GRB 991208, UBVRI field photometry
  59. GRB000301c results
  60. GRB000408: Optical CCD Observations from MIRO
  61. GRB000408, lotis optical observations
  62. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  63. GRB000408 [IPN Position]
  64. GRB000326 Optical Observations
  65. GRB000301C - Addendum to GCN 623
  66. GRB000301C - R magnitude lower limit
  67. GRB000326, Further VLA observations
  68. GRB 000323, optical observations
  69. GRB 000326: Optical Observations
  70. GRB000326, Radio observations
  71. GRB000326 [IPN Position]
  72. GRB 000307 optical observations
  73. GRB000323 [IPN Position]
  74. Single error box for GRB000315
  75. GRB000315 [IPN Positions]
  76. GRB000313, Radio observations
  77. GRB 000313 - optical transient in the BATSE error box
  78. GRB000301C - B and R photometry
  79. GRB000301C - R photometry
  80. GRB 000307, Optical Observations
  81. GRB 000307, BVRI Field Photometry
  82. GRB 000301C: Optical Spectrum and Redshift
  83. GRB 000301C: Optical Spectrum and Redshift
  84. GRB 000301C: A Precise Redshift Determination
  85. GRB 000301C, Optical Observation
  86. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  87. GRB 000301C: HST/STIS CCD Imaging of the field
  88. IPN error box for GRB000307
  89. GRB 000301c: K' observations
  90. GRB000301C, optical R-band observations
  91. GRB000301c - R photometry and nearby faint source confirmation
  92. GRB 000301C, Optical Observation
  93. GRB 000301c: K' observations
  94. GRB 000301C Optical Observations
  95. GRB 000301C: K' Observations
  96. GRB000301C OT candidate optical observations
  97. GRB000301C - Host galaxy not detected in R (?)
  98. Optical observations of GRB000301c
  99. GRB000301C, Radio observations
  100. GRB000301C, Radio observations

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