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