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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. GRB000301C - Addendum to GCN 623
  2. GRB000301C - R magnitude lower limit
  3. GRB000326, Further VLA observations
  4. GRB 000323, optical observations
  5. GRB 000326: Optical Observations
  6. GRB000326, Radio observations
  7. GRB000326 [IPN Position]
  8. GRB 000307 optical observations
  9. GRB000323 [IPN Position]
  10. Single error box for GRB000315
  11. GRB000315 [IPN Positions]
  12. GRB000313, Radio observations
  13. GRB 000313 - optical transient in the BATSE error box
  14. GRB000301C - B and R photometry
  15. GRB000301C - R photometry
  16. GRB 000307, Optical Observations
  17. GRB 000307, BVRI Field Photometry
  18. GRB 000301C: Optical Spectrum and Redshift
  19. GRB 000301C: Optical Spectrum and Redshift
  20. GRB 000301C: A Precise Redshift Determination
  21. GRB 000301C, Optical Observation
  22. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  23. GRB 000301C: HST/STIS CCD Imaging of the field
  24. IPN error box for GRB000307
  25. GRB 000301c: K' observations
  26. GRB000301C, optical R-band observations
  27. GRB000301c - R photometry and nearby faint source confirmation
  28. GRB 000301C, Optical Observation
  29. GRB 000301c: K' observations
  30. GRB 000301C Optical Observations
  31. GRB 000301C: K' Observations
  32. GRB000301C OT candidate optical observations
  33. GRB000301C - Host galaxy not detected in R (?)
  34. Optical observations of GRB000301c
  35. GRB000301C, Radio observations
  36. GRB000301C, Radio observations
  37. GRB000301C optical observations
  38. GRB000301C, near-infrared observations (JHK' imaging)
  39. GRB 000301c near-IR observations
  40. GRB 000301C, Optical Color
  41. GRB000301C, Optical Spectroscopy
  42. GRB 000301C, UBVRI field photometry
  43. GRB 000301C, Optical Observation
  44. GRB000301C, optical observations
  45. GRB000301C 250 GHz detection
  46. GRB 000301C R-band observation
  47. GRB 000301C, Optical Observation
  48. GRB000301C, near-infrared observations (JHK' photometry)
  49. GRB 000301C: OT confirmed
  50. GRB000301c optical observations
  51. GRB 000301A, Radio Observations
  52. GRB000301C, optical observations
  53. GRB000301c, near-infrared observations
  54. GRB000301C
  55. GRB 000301C : Optical Candidate
  56. Radio observations of the error box of GRB000301A
  57. GRB000301C: RXTE/ASM and IPN localizations
  58. GRB000301A [IPN Position]
  59. GRB000226 [IPN Position]
  60. HST Observations of GRB 990712
  61. GRB 000214 near-IR observations
  62. GRB 000115 Optical observations
  63. GRB 000214, Radio Observations
  64. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  65. GRB000210, Radio Observations
  66. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  67. GRB 000115, BVRI field photometry
  68. GRB000214: BeppoSAX GRBM and WFC Detection
  69. IPN annulus for GRB000214
  70. BATSE GRB trigger criterion changed
  71. Optical observations of GRB000210
  72. GRB000210 X-ray afterglow
  73. GRB000214: X-ray afterglow candidate
  74. GRB000214 refined BeppoSAX-WFC position
  75. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  76. GRB 000210: BATSE Observations
  77. Correction to Chandra Position of GRB000210 afterglow
  78. Optical observations of the Chandra X-ray source for GRB000210
  79. GRB000210, Radio Observations
  80. Optical candidate for GRB000210
  81. Chandra Observations of GRB000210 X-ray Afterglow
  82. IPN triangulation of GRB000210
  83. GRB000210: possible afterglow detection with BeppoSAX NFI
  84. GRB000201, Radio Observations
  85. GRB000210: BeppoSAX GRBM and WFC Detection
  86. SAX_WFC_GRB_NOTICE
  87. SAX_WFC_GRB_NOTICE
  88. Optical observations of GRB000131
  89. GRB000201 Optical Observations
  90. GRB 000201: TAROT optical observations
  91. GRB 000131 Optical Observations
  92. GRB000126 Optical Observations
  93. BATSE GRB trigger criteria changed
  94. GRB 991208, radio observations
  95. BATSE+IPN location of GRB000131
  96. IPN localization of GRB000131
  97. GRB 000126, optical observations
  98. GRB000126, optical observations
  99. BATSE location of GRB000126
  100. IPN localization of GRB000126

Advanced

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