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. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  2. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  3. Budget cuts in BeppoSAX operations: impact on GRB observations
  4. GRB 000408, optical observations
  5. Refined IPN error box for GRB000408
  6. GRB 991208, UBVRI field photometry
  7. GRB000301c results
  8. GRB000408: Optical CCD Observations from MIRO
  9. GRB000408, lotis optical observations
  10. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  11. GRB000408 [IPN Position]
  12. GRB000326 Optical Observations
  13. GRB000301C - Addendum to GCN 623
  14. GRB000301C - R magnitude lower limit
  15. GRB000326, Further VLA observations
  16. GRB 000323, optical observations
  17. GRB 000326: Optical Observations
  18. GRB000326, Radio observations
  19. GRB000326 [IPN Position]
  20. GRB 000307 optical observations
  21. GRB000323 [IPN Position]
  22. Single error box for GRB000315
  23. GRB000315 [IPN Positions]
  24. GRB000313, Radio observations
  25. GRB 000313 - optical transient in the BATSE error box
  26. GRB000301C - B and R photometry
  27. GRB000301C - R photometry
  28. GRB 000307, Optical Observations
  29. GRB 000307, BVRI Field Photometry
  30. GRB 000301C: Optical Spectrum and Redshift
  31. GRB 000301C: Optical Spectrum and Redshift
  32. GRB 000301C: A Precise Redshift Determination
  33. GRB 000301C, Optical Observation
  34. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  35. GRB 000301C: HST/STIS CCD Imaging of the field
  36. IPN error box for GRB000307
  37. GRB 000301c: K' observations
  38. GRB000301C, optical R-band observations
  39. GRB000301c - R photometry and nearby faint source confirmation
  40. GRB 000301C, Optical Observation
  41. GRB 000301c: K' observations
  42. GRB 000301C Optical Observations
  43. GRB 000301C: K' Observations
  44. GRB000301C OT candidate optical observations
  45. GRB000301C - Host galaxy not detected in R (?)
  46. Optical observations of GRB000301c
  47. GRB000301C, Radio observations
  48. GRB000301C, Radio observations
  49. GRB000301C optical observations
  50. GRB000301C, near-infrared observations (JHK' imaging)
  51. GRB 000301c near-IR observations
  52. GRB 000301C, Optical Color
  53. GRB000301C, Optical Spectroscopy
  54. GRB 000301C, UBVRI field photometry
  55. GRB 000301C, Optical Observation
  56. GRB000301C, optical observations
  57. GRB000301C 250 GHz detection
  58. GRB 000301C R-band observation
  59. GRB 000301C, Optical Observation
  60. GRB000301C, near-infrared observations (JHK' photometry)
  61. GRB 000301C: OT confirmed
  62. GRB000301c optical observations
  63. GRB 000301A, Radio Observations
  64. GRB000301C, optical observations
  65. GRB000301c, near-infrared observations
  66. GRB000301C
  67. GRB 000301C : Optical Candidate
  68. Radio observations of the error box of GRB000301A
  69. GRB000301C: RXTE/ASM and IPN localizations
  70. GRB000301A [IPN Position]
  71. GRB000226 [IPN Position]
  72. HST Observations of GRB 990712
  73. GRB 000214 near-IR observations
  74. GRB 000115 Optical observations
  75. GRB 000214, Radio Observations
  76. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  77. GRB000210, Radio Observations
  78. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  79. GRB 000115, BVRI field photometry
  80. GRB000214: BeppoSAX GRBM and WFC Detection
  81. IPN annulus for GRB000214
  82. BATSE GRB trigger criterion changed
  83. Optical observations of GRB000210
  84. GRB000210 X-ray afterglow
  85. GRB000214: X-ray afterglow candidate
  86. GRB000214 refined BeppoSAX-WFC position
  87. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  88. GRB 000210: BATSE Observations
  89. Correction to Chandra Position of GRB000210 afterglow
  90. Optical observations of the Chandra X-ray source for GRB000210
  91. GRB000210, Radio Observations
  92. Optical candidate for GRB000210
  93. Chandra Observations of GRB000210 X-ray Afterglow
  94. IPN triangulation of GRB000210
  95. GRB000210: possible afterglow detection with BeppoSAX NFI
  96. GRB000201, Radio Observations
  97. GRB000210: BeppoSAX GRBM and WFC Detection
  98. SAX_WFC_GRB_NOTICE
  99. SAX_WFC_GRB_NOTICE
  100. Optical observations of GRB000131

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