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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. Budget cuts in BeppoSAX operations: impact on GRB observations
  2. GRB 000408, optical observations
  3. Refined IPN error box for GRB000408
  4. GRB 991208, UBVRI field photometry
  5. GRB000301c results
  6. GRB000408: Optical CCD Observations from MIRO
  7. GRB000408, lotis optical observations
  8. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  9. GRB000408 [IPN Position]
  10. GRB000326 Optical Observations
  11. GRB000301C - Addendum to GCN 623
  12. GRB000301C - R magnitude lower limit
  13. GRB000326, Further VLA observations
  14. GRB 000323, optical observations
  15. GRB 000326: Optical Observations
  16. GRB000326, Radio observations
  17. GRB000326 [IPN Position]
  18. GRB 000307 optical observations
  19. GRB000323 [IPN Position]
  20. Single error box for GRB000315
  21. GRB000315 [IPN Positions]
  22. GRB000313, Radio observations
  23. GRB 000313 - optical transient in the BATSE error box
  24. GRB000301C - B and R photometry
  25. GRB000301C - R photometry
  26. GRB 000307, Optical Observations
  27. GRB 000307, BVRI Field Photometry
  28. GRB 000301C: Optical Spectrum and Redshift
  29. GRB 000301C: Optical Spectrum and Redshift
  30. GRB 000301C: A Precise Redshift Determination
  31. GRB 000301C, Optical Observation
  32. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  33. GRB 000301C: HST/STIS CCD Imaging of the field
  34. IPN error box for GRB000307
  35. GRB 000301c: K' observations
  36. GRB000301C, optical R-band observations
  37. GRB000301c - R photometry and nearby faint source confirmation
  38. GRB 000301C, Optical Observation
  39. GRB 000301c: K' observations
  40. GRB 000301C Optical Observations
  41. GRB 000301C: K' Observations
  42. GRB000301C OT candidate optical observations
  43. GRB000301C - Host galaxy not detected in R (?)
  44. Optical observations of GRB000301c
  45. GRB000301C, Radio observations
  46. GRB000301C, Radio observations
  47. GRB000301C optical observations
  48. GRB000301C, near-infrared observations (JHK' imaging)
  49. GRB 000301c near-IR observations
  50. GRB 000301C, Optical Color
  51. GRB000301C, Optical Spectroscopy
  52. GRB 000301C, UBVRI field photometry
  53. GRB 000301C, Optical Observation
  54. GRB000301C, optical observations
  55. GRB000301C 250 GHz detection
  56. GRB 000301C R-band observation
  57. GRB 000301C, Optical Observation
  58. GRB000301C, near-infrared observations (JHK' photometry)
  59. GRB 000301C: OT confirmed
  60. GRB000301c optical observations
  61. GRB 000301A, Radio Observations
  62. GRB000301C, optical observations
  63. GRB000301c, near-infrared observations
  64. GRB000301C
  65. GRB 000301C : Optical Candidate
  66. Radio observations of the error box of GRB000301A
  67. GRB000301C: RXTE/ASM and IPN localizations
  68. GRB000301A [IPN Position]
  69. GRB000226 [IPN Position]
  70. HST Observations of GRB 990712
  71. GRB 000214 near-IR observations
  72. GRB 000115 Optical observations
  73. GRB 000214, Radio Observations
  74. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  75. GRB000210, Radio Observations
  76. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  77. GRB 000115, BVRI field photometry
  78. GRB000214: BeppoSAX GRBM and WFC Detection
  79. IPN annulus for GRB000214
  80. BATSE GRB trigger criterion changed
  81. Optical observations of GRB000210
  82. GRB000210 X-ray afterglow
  83. GRB000214: X-ray afterglow candidate
  84. GRB000214 refined BeppoSAX-WFC position
  85. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  86. GRB 000210: BATSE Observations
  87. Correction to Chandra Position of GRB000210 afterglow
  88. Optical observations of the Chandra X-ray source for GRB000210
  89. GRB000210, Radio Observations
  90. Optical candidate for GRB000210
  91. Chandra Observations of GRB000210 X-ray Afterglow
  92. IPN triangulation of GRB000210
  93. GRB000210: possible afterglow detection with BeppoSAX NFI
  94. GRB000201, Radio Observations
  95. GRB000210: BeppoSAX GRBM and WFC Detection
  96. SAX_WFC_GRB_NOTICE
  97. SAX_WFC_GRB_NOTICE
  98. Optical observations of GRB000131
  99. GRB000201 Optical Observations
  100. GRB 000201: TAROT optical observations

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