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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. GRB 991208, UBVRI field photometry
  2. GRB000301c results
  3. GRB000408: Optical CCD Observations from MIRO
  4. GRB000408, lotis optical observations
  5. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  6. GRB000408 [IPN Position]
  7. GRB000326 Optical Observations
  8. GRB000301C - Addendum to GCN 623
  9. GRB000301C - R magnitude lower limit
  10. GRB000326, Further VLA observations
  11. GRB 000323, optical observations
  12. GRB 000326: Optical Observations
  13. GRB000326, Radio observations
  14. GRB000326 [IPN Position]
  15. GRB 000307 optical observations
  16. GRB000323 [IPN Position]
  17. Single error box for GRB000315
  18. GRB000315 [IPN Positions]
  19. GRB000313, Radio observations
  20. GRB 000313 - optical transient in the BATSE error box
  21. GRB000301C - B and R photometry
  22. GRB000301C - R photometry
  23. GRB 000307, Optical Observations
  24. GRB 000307, BVRI Field Photometry
  25. GRB 000301C: Optical Spectrum and Redshift
  26. GRB 000301C: Optical Spectrum and Redshift
  27. GRB 000301C: A Precise Redshift Determination
  28. GRB 000301C, Optical Observation
  29. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  30. GRB 000301C: HST/STIS CCD Imaging of the field
  31. IPN error box for GRB000307
  32. GRB 000301c: K' observations
  33. GRB000301C, optical R-band observations
  34. GRB000301c - R photometry and nearby faint source confirmation
  35. GRB 000301C, Optical Observation
  36. GRB 000301c: K' observations
  37. GRB 000301C Optical Observations
  38. GRB 000301C: K' Observations
  39. GRB000301C OT candidate optical observations
  40. GRB000301C - Host galaxy not detected in R (?)
  41. Optical observations of GRB000301c
  42. GRB000301C, Radio observations
  43. GRB000301C, Radio observations
  44. GRB000301C optical observations
  45. GRB000301C, near-infrared observations (JHK' imaging)
  46. GRB 000301c near-IR observations
  47. GRB 000301C, Optical Color
  48. GRB000301C, Optical Spectroscopy
  49. GRB 000301C, UBVRI field photometry
  50. GRB 000301C, Optical Observation
  51. GRB000301C, optical observations
  52. GRB000301C 250 GHz detection
  53. GRB 000301C R-band observation
  54. GRB 000301C, Optical Observation
  55. GRB000301C, near-infrared observations (JHK' photometry)
  56. GRB 000301C: OT confirmed
  57. GRB000301c optical observations
  58. GRB 000301A, Radio Observations
  59. GRB000301C, optical observations
  60. GRB000301c, near-infrared observations
  61. GRB000301C
  62. GRB 000301C : Optical Candidate
  63. Radio observations of the error box of GRB000301A
  64. GRB000301C: RXTE/ASM and IPN localizations
  65. GRB000301A [IPN Position]
  66. GRB000226 [IPN Position]
  67. HST Observations of GRB 990712
  68. GRB 000214 near-IR observations
  69. GRB 000115 Optical observations
  70. GRB 000214, Radio Observations
  71. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  72. GRB000210, Radio Observations
  73. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  74. GRB 000115, BVRI field photometry
  75. GRB000214: BeppoSAX GRBM and WFC Detection
  76. IPN annulus for GRB000214
  77. BATSE GRB trigger criterion changed
  78. Optical observations of GRB000210
  79. GRB000210 X-ray afterglow
  80. GRB000214: X-ray afterglow candidate
  81. GRB000214 refined BeppoSAX-WFC position
  82. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  83. GRB 000210: BATSE Observations
  84. Correction to Chandra Position of GRB000210 afterglow
  85. Optical observations of the Chandra X-ray source for GRB000210
  86. GRB000210, Radio Observations
  87. Optical candidate for GRB000210
  88. Chandra Observations of GRB000210 X-ray Afterglow
  89. IPN triangulation of GRB000210
  90. GRB000210: possible afterglow detection with BeppoSAX NFI
  91. GRB000201, Radio Observations
  92. GRB000210: BeppoSAX GRBM and WFC Detection
  93. SAX_WFC_GRB_NOTICE
  94. SAX_WFC_GRB_NOTICE
  95. Optical observations of GRB000131
  96. GRB000201 Optical Observations
  97. GRB 000201: TAROT optical observations
  98. GRB 000131 Optical Observations
  99. GRB000126 Optical Observations
  100. BATSE GRB trigger criteria changed

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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