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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. GRB000528, Radio Observations
  2. X-ray Afterglow of GRB 000529
  3. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  4. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  5. GRB000529: Optical Observations
  6. IPN localization and time history of GRB000528
  7. New IPN localization of GRB000529
  8. GRB000519: Optical observations
  9. IPN localization of GRB000529
  10. GRB 000528 - WFC measurements
  11. GRB000529: BeppoSAX WFC position
  12. GRB000528: BeppoSAX GRBM observations
  13. GRB 000528 Optical Observations
  14. GRB000519, BVRI field photometry
  15. IPN triangulation of GRB000519
  16. IPN triangulation of GRB000516
  17. Re: GRB000508B : Optical observations
  18. GRB 000418, Optical observation
  19. GRB000508B, optical photometry
  20. GRB000508B, BVR field photometry
  21. Possible GRB-related phenomenon
  22. RXTE/ASM and IPN localization of GRB 000508B
  23. GRB000424, UBVRI field photometry
  24. GRB 000424 Optical Observations
  25. GRB000418, UBVRI field photometry update
  26. The redshift of GRB 000418
  27. GRB000424, optical observations
  28. GRB 000429, optical observation
  29. GRB 000429, UBVRI field photometry
  30. IPN localization of GRB000429
  31. GRB 000418, UBVRI field photometry
  32. GRB000418, Radio detection
  33. GRB000418, K'-band photometry
  34. GRB 000418, Optical Observation
  35. GRB 000418, optical observation
  36. GRB000424 Optical Observations
  37. GRB 000418, Optical Observation
  38. GRB000424, optical observations
  39. GRB000424, optical observations
  40. GRB 000424, Optical Observations
  41. GRB 000418, Optical Observation
  42. GRB000418, near-infrared observations
  43. BeppoSAX GRB000424
  44. Correction to IPN error box for GRB000419
  45. IPN error box for GRB000418
  46. GRB000419 [IPN Position]
  47. GRB000416 Optical Observations
  48. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  49. GRB000416 BRJK observations
  50. 1SAXJ1715.0-7134 refined position
  51. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  52. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  53. Budget cuts in BeppoSAX operations: impact on GRB observations
  54. GRB 000408, optical observations
  55. Refined IPN error box for GRB000408
  56. GRB 991208, UBVRI field photometry
  57. GRB000301c results
  58. GRB000408: Optical CCD Observations from MIRO
  59. GRB000408, lotis optical observations
  60. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  61. GRB000408 [IPN Position]
  62. GRB000326 Optical Observations
  63. GRB000301C - Addendum to GCN 623
  64. GRB000301C - R magnitude lower limit
  65. GRB000326, Further VLA observations
  66. GRB 000323, optical observations
  67. GRB 000326: Optical Observations
  68. GRB000326, Radio observations
  69. GRB000326 [IPN Position]
  70. GRB 000307 optical observations
  71. GRB000323 [IPN Position]
  72. Single error box for GRB000315
  73. GRB000315 [IPN Positions]
  74. GRB000313, Radio observations
  75. GRB 000313 - optical transient in the BATSE error box
  76. GRB000301C - B and R photometry
  77. GRB000301C - R photometry
  78. GRB 000307, Optical Observations
  79. GRB 000307, BVRI Field Photometry
  80. GRB 000301C: Optical Spectrum and Redshift
  81. GRB 000301C: Optical Spectrum and Redshift
  82. GRB 000301C: A Precise Redshift Determination
  83. GRB 000301C, Optical Observation
  84. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  85. GRB 000301C: HST/STIS CCD Imaging of the field
  86. IPN error box for GRB000307
  87. GRB 000301c: K' observations
  88. GRB000301C, optical R-band observations
  89. GRB000301c - R photometry and nearby faint source confirmation
  90. GRB 000301C, Optical Observation
  91. GRB 000301c: K' observations
  92. GRB 000301C Optical Observations
  93. GRB 000301C: K' Observations
  94. GRB000301C OT candidate optical observations
  95. GRB000301C - Host galaxy not detected in R (?)
  96. Optical observations of GRB000301c
  97. GRB000301C, Radio observations
  98. GRB000301C, Radio observations
  99. GRB000301C optical observations
  100. GRB000301C, near-infrared observations (JHK' imaging)

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