Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"

24753 results found.

  1. IPN triangulation of GRB000519
  2. GRB000508B, optical photometry
  3. GRB000508B, BVR field photometry
  4. Possible GRB-related phenomenon
  5. RXTE/ASM and IPN localization of GRB 000508B
  6. GRB000424, UBVRI field photometry
  7. GRB000418, UBVRI field photometry update
  8. GRB000424, optical observations
  9. GRB 000429, optical observation
  10. GRB 000429, UBVRI field photometry
  11. GRB 000418, UBVRI field photometry
  12. GRB 000418, optical observation
  13. GRB 000418, Optical Observation
  14. GRB000418, near-infrared observations
  15. Correction to IPN error box for GRB000419
  16. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  17. GRB000416 BRJK observations
  18. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  19. GRB 000408, optical observations
  20. GRB 991208, UBVRI field photometry
  21. GRB000408, lotis optical observations
  22. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  23. GRB000301C - Addendum to GCN 623
  24. GRB 000323, optical observations
  25. GRB 000326: Optical Observations
  26. GRB000326, Radio observations
  27. GRB000313, Radio observations
  28. GRB 000313 - optical transient in the BATSE error box
  29. GRB 000307, Optical Observations
  30. GRB 000307, BVRI Field Photometry
  31. GRB 000301C: A Precise Redshift Determination
  32. GRB 000301C, Optical Observation
  33. GRB 000301C: HST/STIS CCD Imaging of the field
  34. IPN error box for GRB000307
  35. GRB000301C, optical R-band observations
  36. GRB 000301C Optical Observations
  37. GRB 000301C: K' Observations
  38. GRB000301C OT candidate optical observations
  39. GRB000301C - Host galaxy not detected in R (?)
  40. Optical observations of GRB000301c
  41. GRB000301C, Radio observations
  42. GRB000301C, Radio observations
  43. GRB000301C, near-infrared observations (JHK' imaging)
  44. GRB 000301c near-IR observations
  45. GRB 000301C, UBVRI field photometry
  46. GRB 000301C: OT confirmed
  47. GRB000301c optical observations
  48. GRB000301C, optical observations
  49. GRB000301C
  50. GRB 000301C : Optical Candidate
  51. GRB000301C: RXTE/ASM and IPN localizations
  52. GRB000226 [IPN Position]
  53. HST Observations of GRB 990712
  54. GRB 000214 near-IR observations
  55. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  56. GRB000210, Radio Observations
  57. GRB 000115, BVRI field photometry
  58. GRB000214: BeppoSAX GRBM and WFC Detection
  59. Optical observations of GRB000210
  60. GRB000210 X-ray afterglow
  61. GRB000214: X-ray afterglow candidate
  62. GRB000214 refined BeppoSAX-WFC position
  63. GRB 000210: BATSE Observations
  64. Optical observations of the Chandra X-ray source for GRB000210
  65. GRB000210, Radio Observations
  66. IPN triangulation of GRB000210
  67. GRB000210: possible afterglow detection with BeppoSAX NFI
  68. GRB000201, Radio Observations
  69. GRB000210: BeppoSAX GRBM and WFC Detection
  70. SAX_WFC_GRB_NOTICE
  71. SAX_WFC_GRB_NOTICE
  72. GRB000201 Optical Observations
  73. GRB 000201: TAROT optical observations
  74. GRB 991208, radio observations
  75. BATSE+IPN location of GRB000131
  76. IPN localization of GRB000131
  77. GRB 000126, optical observations
  78. BATSE Observations of GRB000115
  79. Second RXTE Observation of GRB 000115
  80. GRB991216, UBVRIJHK field photometry
  81. GCN resumes full operations
  82. GRB 991216 VLBA Observations
  83. GRB 991216: J band spectrophotometry
  84. GRB 991216: Detection of the Host and/or Absorber Galaxy
  85. IPN localization of GRB991226
  86. GRB 991216 RXTE ASM Observations
  87. GRB 991216: Updated BATSE parameters
  88. GRB 991217 (SAX J2303.2+0015) Optical observations
  89. Chandra observation of the X-ray afterglow of GRB991216
  90. GRB 991216, optical observations
  91. GRB 991216 Optical spectroscopy/imaging
  92. SAX J2303.2+0015 Optical observations
  93. IR observations of GRB991216
  94. GRB 991217 (SAX J2303.2+0015) Optical observations
  95. GRB991216 Optical and infrared observations of Beethoven Burst
  96. GRB 991216 Radio Observations
  97. GRB 991208 Keck Spectroscopy
  98. GRB 991208 Infrared Detection
  99. GRB991216
  100. GRB 991216--Summary of RXTE 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