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"

37201 results found.

  1. GRB000301C - R magnitude lower limit
  2. GRB 000323, optical observations
  3. GRB 000326: Optical Observations
  4. GRB000326, Radio observations
  5. GRB000326 [IPN Position]
  6. GRB 000307 optical observations
  7. GRB000323 [IPN Position]
  8. GRB000315 [IPN Positions]
  9. GRB 000313 - optical transient in the BATSE error box
  10. GRB000301C - B and R photometry
  11. GRB000301C - R photometry
  12. GRB 000307, Optical Observations
  13. GRB 000307, BVRI Field Photometry
  14. GRB 000301C: Optical Spectrum and Redshift
  15. GRB 000301C: Optical Spectrum and Redshift
  16. GRB 000301C: A Precise Redshift Determination
  17. GRB 000301C, Optical Observation
  18. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  19. GRB 000301C: HST/STIS CCD Imaging of the field
  20. IPN error box for GRB000307
  21. GRB 000301c: K' observations
  22. GRB000301C, optical R-band observations
  23. GRB000301c - R photometry and nearby faint source confirmation
  24. GRB 000301C, Optical Observation
  25. GRB 000301c: K' observations
  26. GRB 000301C Optical Observations
  27. GRB 000301C: K' Observations
  28. GRB000301C - Host galaxy not detected in R (?)
  29. GRB000301C optical observations
  30. GRB 000301c near-IR observations
  31. GRB 000301C, Optical Color
  32. GRB000301C, Optical Spectroscopy
  33. GRB 000301C, UBVRI field photometry
  34. GRB 000301C, Optical Observation
  35. GRB000301C 250 GHz detection
  36. GRB 000301C R-band observation
  37. GRB 000301C, Optical Observation
  38. GRB000301C, near-infrared observations (JHK' photometry)
  39. GRB 000301C: OT confirmed
  40. GRB000301c optical observations
  41. GRB 000301A, Radio Observations
  42. GRB000301C, optical observations
  43. GRB000301c, near-infrared observations
  44. GRB000301C
  45. GRB 000301C : Optical Candidate
  46. GRB000301C: RXTE/ASM and IPN localizations
  47. GRB000226 [IPN Position]
  48. HST Observations of GRB 990712
  49. GRB 000214 near-IR observations
  50. GRB 000115 Optical observations
  51. GRB 000214, Radio Observations
  52. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  53. GRB 000115, BVRI field photometry
  54. IPN annulus for GRB000214
  55. BATSE GRB trigger criterion changed
  56. GRB000210 X-ray afterglow
  57. GRB000214: X-ray afterglow candidate
  58. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  59. GRB 000210: BATSE Observations
  60. Optical observations of the Chandra X-ray source for GRB000210
  61. Chandra Observations of GRB000210 X-ray Afterglow
  62. IPN triangulation of GRB000210
  63. GRB 000201: TAROT optical observations
  64. GRB 000131 Optical Observations
  65. GRB000126 Optical Observations
  66. BATSE GRB trigger criteria changed
  67. GRB 991208, radio observations
  68. BATSE+IPN location of GRB000131
  69. IPN localization of GRB000131
  70. GRB 000126, optical observations
  71. GRB000126, optical observations
  72. BATSE location of GRB000126
  73. IPN localization of GRB000126
  74. GRB 000115 Optical observations
  75. BATSE Observations of GRB000115
  76. Second RXTE Observation of GRB 000115
  77. GRB991216, UBVRIJHK field photometry
  78. Single IPN error box for GRB991229
  79. GRB 991216 VLBA Observations
  80. BEPPOSAX GRBM Localization of GRB991226
  81. IPN error boxes for GRB991229
  82. GRB 991216: J band spectrophotometry
  83. GRB 991216: Detection of the Host and/or Absorber Galaxy
  84. IPN localization of GRB991226
  85. Single IPN error box for GRB991221
  86. IPN error boxes for GRB991221
  87. GRB 991216 RXTE ASM Observations
  88. IPN error box for GRB991216
  89. GRB 991216: Updated BATSE parameters
  90. Lowell/Perkins observation of GRB 991216
  91. GRB 991217 (SAX J2303.2+0015) Optical observations
  92. Chandra observation of the X-ray afterglow of GRB991216
  93. GRB 991216, optical observations
  94. GRB 991216 Optical Observations
  95. GRB 991216 Optical spectroscopy/imaging
  96. K observations of GRB991216
  97. GRB 991217 (SAX J2303.2+0015) Optical observations
  98. GRB991216 Spectroscopy
  99. Lowell/Perkins observation of GRB 991216
  100. GRB991216, 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