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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').
  1. GRB 000326: Optical Observations
  2. GRB000326, Radio observations
  3. GRB000326 [IPN Position]
  4. GRB 000307 optical observations
  5. GRB000323 [IPN Position]
  6. Single error box for GRB000315
  7. GRB000315 [IPN Positions]
  8. GRB000313, Radio observations
  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 OT candidate optical observations
  29. GRB000301C - Host galaxy not detected in R (?)
  30. Optical observations of GRB000301c
  31. GRB000301C, Radio observations
  32. GRB000301C, Radio observations
  33. GRB000301C optical observations
  34. GRB000301C, near-infrared observations (JHK' imaging)
  35. GRB 000301c near-IR observations
  36. GRB 000301C, Optical Color
  37. GRB000301C, Optical Spectroscopy
  38. GRB 000301C, UBVRI field photometry
  39. GRB 000301C, Optical Observation
  40. GRB000301C, optical observations
  41. GRB000301C 250 GHz detection
  42. GRB 000301C R-band observation
  43. GRB 000301C, Optical Observation
  44. GRB000301C, near-infrared observations (JHK' photometry)
  45. GRB 000301C: OT confirmed
  46. GRB000301c optical observations
  47. GRB 000301A, Radio Observations
  48. GRB000301C, optical observations
  49. GRB000301c, near-infrared observations
  50. GRB000301C
  51. GRB 000301C : Optical Candidate
  52. Radio observations of the error box of GRB000301A
  53. GRB000301C: RXTE/ASM and IPN localizations
  54. GRB000301A [IPN Position]
  55. GRB000226 [IPN Position]
  56. HST Observations of GRB 990712
  57. GRB 000214 near-IR observations
  58. GRB 000115 Optical observations
  59. GRB 000214, Radio Observations
  60. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  61. GRB000210, Radio Observations
  62. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  63. GRB 000115, BVRI field photometry
  64. GRB000214: BeppoSAX GRBM and WFC Detection
  65. IPN annulus for GRB000214
  66. BATSE GRB trigger criterion changed
  67. Optical observations of GRB000210
  68. GRB000210 X-ray afterglow
  69. GRB000214: X-ray afterglow candidate
  70. GRB000214 refined BeppoSAX-WFC position
  71. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  72. GRB 000210: BATSE Observations
  73. Correction to Chandra Position of GRB000210 afterglow
  74. Optical observations of the Chandra X-ray source for GRB000210
  75. GRB000210, Radio Observations
  76. Optical candidate for GRB000210
  77. Chandra Observations of GRB000210 X-ray Afterglow
  78. IPN triangulation of GRB000210
  79. GRB000210: possible afterglow detection with BeppoSAX NFI
  80. GRB000201, Radio Observations
  81. GRB000210: BeppoSAX GRBM and WFC Detection
  82. SAX_WFC_GRB_NOTICE
  83. SAX_WFC_GRB_NOTICE
  84. Optical observations of GRB000131
  85. GRB000201 Optical Observations
  86. GRB 000201: TAROT optical observations
  87. GRB 000131 Optical Observations
  88. GRB000126 Optical Observations
  89. BATSE GRB trigger criteria changed
  90. GRB 991208, radio observations
  91. BATSE+IPN location of GRB000131
  92. IPN localization of GRB000131
  93. GRB 000126, optical observations
  94. GRB000126, optical observations
  95. BATSE location of GRB000126
  96. IPN localization of GRB000126
  97. GRB 000115 Optical observations
  98. BATSE Observations of GRB000115
  99. Correction to GCN 520 (IPN annulus for GRB000115)
  100. IPN annulus for GRB000115

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