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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. GRB000326, Further VLA observations
  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. Single error box for GRB000315
  9. GRB000315 [IPN Positions]
  10. GRB000313, Radio observations
  11. GRB 000313 - optical transient in the BATSE error box
  12. GRB000301C - B and R photometry
  13. GRB000301C - R photometry
  14. GRB 000307, Optical Observations
  15. GRB 000307, BVRI Field Photometry
  16. GRB 000301C: Optical Spectrum and Redshift
  17. GRB 000301C: Optical Spectrum and Redshift
  18. GRB 000301C: A Precise Redshift Determination
  19. GRB 000301C, Optical Observation
  20. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  21. GRB 000301C: HST/STIS CCD Imaging of the field
  22. IPN error box for GRB000307
  23. GRB 000301c: K' observations
  24. GRB000301C, optical R-band observations
  25. GRB000301c - R photometry and nearby faint source confirmation
  26. GRB 000301C, Optical Observation
  27. GRB 000301c: K' observations
  28. GRB 000301C Optical Observations
  29. GRB 000301C: K' Observations
  30. GRB000301C OT candidate optical observations
  31. GRB000301C - Host galaxy not detected in R (?)
  32. Optical observations of GRB000301c
  33. GRB000301C, Radio observations
  34. GRB000301C, Radio observations
  35. GRB000301C optical observations
  36. GRB000301C, near-infrared observations (JHK' imaging)
  37. GRB 000301c near-IR observations
  38. GRB 000301C, Optical Color
  39. GRB000301C, Optical Spectroscopy
  40. GRB 000301C, UBVRI field photometry
  41. GRB 000301C, Optical Observation
  42. GRB000301C, optical observations
  43. GRB000301C 250 GHz detection
  44. GRB 000301C R-band observation
  45. GRB 000301C, Optical Observation
  46. GRB000301C, near-infrared observations (JHK' photometry)
  47. GRB 000301C: OT confirmed
  48. GRB000301c optical observations
  49. GRB 000301A, Radio Observations
  50. GRB000301C, optical observations
  51. GRB000301c, near-infrared observations
  52. GRB000301C
  53. GRB 000301C : Optical Candidate
  54. Radio observations of the error box of GRB000301A
  55. GRB000301C: RXTE/ASM and IPN localizations
  56. GRB000301A [IPN Position]
  57. GRB000226 [IPN Position]
  58. HST Observations of GRB 990712
  59. GRB 000214 near-IR observations
  60. GRB 000115 Optical observations
  61. GRB 000214, Radio Observations
  62. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  63. GRB000210, Radio Observations
  64. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  65. GRB 000115, BVRI field photometry
  66. GRB000214: BeppoSAX GRBM and WFC Detection
  67. IPN annulus for GRB000214
  68. BATSE GRB trigger criterion changed
  69. Optical observations of GRB000210
  70. GRB000210 X-ray afterglow
  71. GRB000214: X-ray afterglow candidate
  72. GRB000214 refined BeppoSAX-WFC position
  73. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  74. GRB 000210: BATSE Observations
  75. Correction to Chandra Position of GRB000210 afterglow
  76. Optical observations of the Chandra X-ray source for GRB000210
  77. GRB000210, Radio Observations
  78. Optical candidate for GRB000210
  79. Chandra Observations of GRB000210 X-ray Afterglow
  80. IPN triangulation of GRB000210
  81. GRB000210: possible afterglow detection with BeppoSAX NFI
  82. GRB000201, Radio Observations
  83. GRB000210: BeppoSAX GRBM and WFC Detection
  84. SAX_WFC_GRB_NOTICE
  85. SAX_WFC_GRB_NOTICE
  86. Optical observations of GRB000131
  87. GRB000201 Optical Observations
  88. GRB 000201: TAROT optical observations
  89. GRB 000131 Optical Observations
  90. GRB000126 Optical Observations
  91. BATSE GRB trigger criteria changed
  92. GRB 991208, radio observations
  93. BATSE+IPN location of GRB000131
  94. IPN localization of GRB000131
  95. GRB 000126, optical observations
  96. GRB000126, optical observations
  97. BATSE location of GRB000126
  98. IPN localization of GRB000126
  99. GRB 000115 Optical observations
  100. BATSE Observations of GRB000115

Advanced

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