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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. GRB000424, optical observations
  2. GRB000424, optical observations
  3. GRB 000424, Optical Observations
  4. GRB 000418, Optical Observation
  5. GRB000418, near-infrared observations
  6. BeppoSAX GRB000424
  7. Correction to IPN error box for GRB000419
  8. IPN error box for GRB000418
  9. GRB000419 [IPN Position]
  10. GRB000416 Optical Observations
  11. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  12. GRB000416 BRJK observations
  13. 1SAXJ1715.0-7134 refined position
  14. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  15. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  16. Budget cuts in BeppoSAX operations: impact on GRB observations
  17. GRB 000408, optical observations
  18. Refined IPN error box for GRB000408
  19. GRB 991208, UBVRI field photometry
  20. GRB000301c results
  21. GRB000408: Optical CCD Observations from MIRO
  22. GRB000408, lotis optical observations
  23. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  24. GRB000408 [IPN Position]
  25. GRB000326 Optical Observations
  26. GRB000301C - Addendum to GCN 623
  27. GRB000301C - R magnitude lower limit
  28. GRB000326, Further VLA observations
  29. GRB 000323, optical observations
  30. GRB 000326: Optical Observations
  31. GRB000326, Radio observations
  32. GRB000326 [IPN Position]
  33. GRB 000307 optical observations
  34. GRB000323 [IPN Position]
  35. Single error box for GRB000315
  36. GRB000315 [IPN Positions]
  37. GRB000313, Radio observations
  38. GRB 000313 - optical transient in the BATSE error box
  39. GRB000301C - B and R photometry
  40. GRB000301C - R photometry
  41. GRB 000307, Optical Observations
  42. GRB 000307, BVRI Field Photometry
  43. GRB 000301C: Optical Spectrum and Redshift
  44. GRB 000301C: Optical Spectrum and Redshift
  45. GRB 000301C: A Precise Redshift Determination
  46. GRB 000301C, Optical Observation
  47. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  48. GRB 000301C: HST/STIS CCD Imaging of the field
  49. IPN error box for GRB000307
  50. GRB 000301c: K' observations
  51. GRB000301C, optical R-band observations
  52. GRB000301c - R photometry and nearby faint source confirmation
  53. GRB 000301C, Optical Observation
  54. GRB 000301c: K' observations
  55. GRB 000301C Optical Observations
  56. GRB 000301C: K' Observations
  57. GRB000301C OT candidate optical observations
  58. GRB000301C - Host galaxy not detected in R (?)
  59. Optical observations of GRB000301c
  60. GRB000301C, Radio observations
  61. GRB000301C, Radio observations
  62. GRB000301C optical observations
  63. GRB000301C, near-infrared observations (JHK' imaging)
  64. GRB 000301c near-IR observations
  65. GRB 000301C, Optical Color
  66. GRB000301C, Optical Spectroscopy
  67. GRB 000301C, UBVRI field photometry
  68. GRB 000301C, Optical Observation
  69. GRB000301C, optical observations
  70. GRB000301C 250 GHz detection
  71. GRB 000301C R-band observation
  72. GRB 000301C, Optical Observation
  73. GRB000301C, near-infrared observations (JHK' photometry)
  74. GRB 000301C: OT confirmed
  75. GRB000301c optical observations
  76. GRB 000301A, Radio Observations
  77. GRB000301C, optical observations
  78. GRB000301c, near-infrared observations
  79. GRB000301C
  80. GRB 000301C : Optical Candidate
  81. Radio observations of the error box of GRB000301A
  82. GRB000301C: RXTE/ASM and IPN localizations
  83. GRB000301A [IPN Position]
  84. GRB000226 [IPN Position]
  85. HST Observations of GRB 990712
  86. GRB 000214 near-IR observations
  87. GRB 000115 Optical observations
  88. GRB 000214, Radio Observations
  89. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  90. GRB000210, Radio Observations
  91. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  92. GRB 000115, BVRI field photometry
  93. GRB000214: BeppoSAX GRBM and WFC Detection
  94. IPN annulus for GRB000214
  95. BATSE GRB trigger criterion changed
  96. Optical observations of GRB000210
  97. GRB000210 X-ray afterglow
  98. GRB000214: X-ray afterglow candidate
  99. GRB000214 refined BeppoSAX-WFC position
  100. BeppoSAX GRB000214 ("S. Valentine's day GRB")

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