Skip to main content
New! Circulars over Kafka, Heartbeat Topic, and Schema v4.1.0. 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').
  1. 1SAXJ1715.0-7134 refined position
  2. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  3. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  4. Budget cuts in BeppoSAX operations: impact on GRB observations
  5. GRB 000408, optical observations
  6. Refined IPN error box for GRB000408
  7. GRB 991208, UBVRI field photometry
  8. GRB000301c results
  9. GRB000408: Optical CCD Observations from MIRO
  10. GRB000408, lotis optical observations
  11. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  12. GRB000408 [IPN Position]
  13. GRB000326 Optical Observations
  14. GRB000301C - Addendum to GCN 623
  15. GRB000301C - R magnitude lower limit
  16. GRB000326, Further VLA observations
  17. GRB 000323, optical observations
  18. GRB 000326: Optical Observations
  19. GRB000326, Radio observations
  20. GRB000326 [IPN Position]
  21. GRB 000307 optical observations
  22. GRB000323 [IPN Position]
  23. Single error box for GRB000315
  24. GRB000315 [IPN Positions]
  25. GRB000313, Radio observations
  26. GRB 000313 - optical transient in the BATSE error box
  27. GRB000301C - B and R photometry
  28. GRB000301C - R photometry
  29. GRB 000307, Optical Observations
  30. GRB 000307, BVRI Field Photometry
  31. GRB 000301C: Optical Spectrum and Redshift
  32. GRB 000301C: Optical Spectrum and Redshift
  33. GRB 000301C: A Precise Redshift Determination
  34. GRB 000301C, Optical Observation
  35. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  36. GRB 000301C: HST/STIS CCD Imaging of the field
  37. IPN error box for GRB000307
  38. GRB 000301c: K' observations
  39. GRB000301C, optical R-band observations
  40. GRB000301c - R photometry and nearby faint source confirmation
  41. GRB 000301C, Optical Observation
  42. GRB 000301c: K' observations
  43. GRB 000301C Optical Observations
  44. GRB 000301C: K' Observations
  45. GRB000301C OT candidate optical observations
  46. GRB000301C - Host galaxy not detected in R (?)
  47. Optical observations of GRB000301c
  48. GRB000301C, Radio observations
  49. GRB000301C, Radio observations
  50. GRB000301C optical observations
  51. GRB000301C, near-infrared observations (JHK' imaging)
  52. GRB 000301c near-IR observations
  53. GRB 000301C, Optical Color
  54. GRB000301C, Optical Spectroscopy
  55. GRB 000301C, UBVRI field photometry
  56. GRB 000301C, Optical Observation
  57. GRB000301C, optical observations
  58. GRB000301C 250 GHz detection
  59. GRB 000301C R-band observation
  60. GRB 000301C, Optical Observation
  61. GRB000301C, near-infrared observations (JHK' photometry)
  62. GRB 000301C: OT confirmed
  63. GRB000301c optical observations
  64. GRB 000301A, Radio Observations
  65. GRB000301C, optical observations
  66. GRB000301c, near-infrared observations
  67. GRB000301C
  68. GRB 000301C : Optical Candidate
  69. Radio observations of the error box of GRB000301A
  70. GRB000301C: RXTE/ASM and IPN localizations
  71. GRB000301A [IPN Position]
  72. GRB000226 [IPN Position]
  73. HST Observations of GRB 990712
  74. GRB 000214 near-IR observations
  75. GRB 000115 Optical observations
  76. GRB 000214, Radio Observations
  77. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  78. GRB000210, Radio Observations
  79. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  80. GRB 000115, BVRI field photometry
  81. GRB000214: BeppoSAX GRBM and WFC Detection
  82. IPN annulus for GRB000214
  83. BATSE GRB trigger criterion changed
  84. Optical observations of GRB000210
  85. GRB000210 X-ray afterglow
  86. GRB000214: X-ray afterglow candidate
  87. GRB000214 refined BeppoSAX-WFC position
  88. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  89. GRB 000210: BATSE Observations
  90. Correction to Chandra Position of GRB000210 afterglow
  91. Optical observations of the Chandra X-ray source for GRB000210
  92. GRB000210, Radio Observations
  93. Optical candidate for GRB000210
  94. Chandra Observations of GRB000210 X-ray Afterglow
  95. IPN triangulation of GRB000210
  96. GRB000210: possible afterglow detection with BeppoSAX NFI
  97. GRB000201, Radio Observations
  98. GRB000210: BeppoSAX GRBM and WFC Detection
  99. SAX_WFC_GRB_NOTICE
  100. SAX_WFC_GRB_NOTICE

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