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"

27322 results found.

  1. GRB 000301C, Optical Observation
  2. GRB 000301C: HST/STIS CCD Imaging of the field
  3. IPN error box for GRB000307
  4. GRB000301C, optical R-band observations
  5. GRB 000301C Optical Observations
  6. GRB 000301C: K' Observations
  7. GRB000301C OT candidate optical observations
  8. GRB000301C - Host galaxy not detected in R (?)
  9. Optical observations of GRB000301c
  10. GRB000301C, Radio observations
  11. GRB000301C, Radio observations
  12. GRB000301C, near-infrared observations (JHK' imaging)
  13. GRB 000301c near-IR observations
  14. GRB 000301C, UBVRI field photometry
  15. GRB 000301C: OT confirmed
  16. GRB000301c optical observations
  17. GRB000301C, optical observations
  18. GRB000301C
  19. GRB 000301C : Optical Candidate
  20. GRB000301C: RXTE/ASM and IPN localizations
  21. GRB000226 [IPN Position]
  22. HST Observations of GRB 990712
  23. GRB 000214 near-IR observations
  24. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  25. GRB000210, Radio Observations
  26. GRB 000115, BVRI field photometry
  27. GRB000214: BeppoSAX GRBM and WFC Detection
  28. Optical observations of GRB000210
  29. GRB000210 X-ray afterglow
  30. GRB000214: X-ray afterglow candidate
  31. GRB000214 refined BeppoSAX-WFC position
  32. GRB 000210: BATSE Observations
  33. Optical observations of the Chandra X-ray source for GRB000210
  34. GRB000210, Radio Observations
  35. IPN triangulation of GRB000210
  36. GRB000210: possible afterglow detection with BeppoSAX NFI
  37. GRB000201, Radio Observations
  38. GRB000210: BeppoSAX GRBM and WFC Detection
  39. SAX_WFC_GRB_NOTICE
  40. SAX_WFC_GRB_NOTICE
  41. GRB000201 Optical Observations
  42. GRB 000201: TAROT optical observations
  43. GRB 991208, radio observations
  44. BATSE+IPN location of GRB000131
  45. IPN localization of GRB000131
  46. GRB 000126, optical observations
  47. BATSE Observations of GRB000115
  48. Second RXTE Observation of GRB 000115
  49. GRB991216, UBVRIJHK field photometry
  50. GCN resumes full operations
  51. GRB 991216 VLBA Observations
  52. GRB 991216: J band spectrophotometry
  53. GRB 991216: Detection of the Host and/or Absorber Galaxy
  54. IPN localization of GRB991226
  55. GRB 991216 RXTE ASM Observations
  56. GRB 991216: Updated BATSE parameters
  57. GRB 991217 (SAX J2303.2+0015) Optical observations
  58. Chandra observation of the X-ray afterglow of GRB991216
  59. GRB 991216, optical observations
  60. GRB 991216 Optical spectroscopy/imaging
  61. SAX J2303.2+0015 Optical observations
  62. IR observations of GRB991216
  63. GRB 991217 (SAX J2303.2+0015) Optical observations
  64. GRB991216 Optical and infrared observations of Beethoven Burst
  65. GRB 991216 Radio Observations
  66. GRB 991208 Keck Spectroscopy
  67. GRB 991208 Infrared Detection
  68. GRB991216
  69. GRB 991216--Summary of RXTE Observations
  70. GRB 991216 Optical Observations
  71. GRB 991216, optical observations
  72. GRB 991208 SAO-RAS Spectroscopy
  73. SAX J2303.2+0015: an x-ray/GRB?
  74. GRB 991216, Optical Transient
  75. GRB991216 ('Beethoven Burst') B, R, and K Observations
  76. GRB991216, infrared observations
  77. GRB 991208 optical observations
  78. GRB 991216 Optical Observation
  79. GRB 991216: Extremely bright BATSE burst
  80. R-band Observations of GRB991208 at TNG
  81. GRB991208, optical observations
  82. GRB 991208, Optical Observation
  83. GRB991208, optical observations
  84. GRB 991208 optical observations
  85. Optical Observations of GRB991105
  86. GRB991106: BeppoSAX/BATSE results
  87. GRB991106, near-infrared observations
  88. BeppoSAX NFI Observation of GRB991106
  89. GRB 991106, radio observations
  90. GRB991106: the first BeppoSAX short GRB detection?
  91. GRB 991105: BATSE Observations
  92. GRB 991106 Optical Observations
  93. GRB991106, optical observation at SAO-RAS
  94. GRB 991106, LOTIS Optical Observations
  95. GRB991105: SAX-GRBM/-WFC detection
  96. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  97. GRB 991014, Optical Observations
  98. GRB 991014 - BeppoSAX NFI observations
  99. GRB 991014, radio observations
  100. GRB 991014, 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