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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 000926: Lightcurve Update and Predictions
  2. GRB 000926, optical observation by Oksanen (vsnet-grb)
  3. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  4. GRB000926: Optical observations
  5. CONCAM crude optical limits before and after GRB000926
  6. GRB 000926: Preliminary R-band Lightcurve
  7. GRB 000926 HST/Chandra TOO Status
  8. Spectroscopic Redshift of GRB 000926
  9. GRB 000926, Optical Observation
  10. GRB000926, radio observations
  11. GRB 000926: Optical candidate
  12. Optical candidate for GRB000926
  13. IPN triangulation of GRB000926
  14. IPN triangulation of GRB000926
  15. GRB 000911, BVRI field photometry
  16. GRB000911: Corrected coordinates
  17. GRB000911: Sub-millimeter observations
  18. IPN triangulation of GRB000925
  19. GRB000911: Optical Transient
  20. GRB000911, Radio and Optical observations
  21. GRB000911, Radio observations
  22. GRB000911: Optical observations
  23. IPN triangulation of GRB000911
  24. IPN triangulation of GRB000910
  25. False GRB alarm from RXTE/ASM on 8 Sept 2000
  26. GRB 000830: Optical observations
  27. GRB000830: Optical observations
  28. GRB000830, TNG B-band observations
  29. GRB000830, BVRI field photometry
  30. GRB000830: Optical observations
  31. GRB000210, Optical observations
  32. Chandra Position of GRB000210
  33. "Snapshot" afterglow IDs and GRB 000830
  34. GRB000830: Optical observations
  35. IPN triangulation of GRB000830
  36. HST/STIS observations of the host galaxy of GRB 980329
  37. HST/STIS observations of the chaotic environment of GRB 980613
  38. IPN localization of GRB000820
  39. SGR 1806-20 burst activity
  40. GRB000812, TNG R-band observations
  41. GRB000801 & GRB000730, Gamma Ray Observations
  42. GRB000730, Gamma Ray Observations
  43. GRB000812, Radio observations
  44. IPN localization of GRB000812
  45. IPN localization of GRB000811
  46. GRB000801, Gamma Ray Observations
  47. GRB000801, VLT-Antu R-band observations
  48. GRB000301C, UBVI optical observations
  49. GRB000801, Radio Observations
  50. GRB 991208 Host Galaxy Imaging
  51. Updated IPN coordinates for GRB000801
  52. IPN localization of GRB000801
  53. IPN localization of GRB000801
  54. IPN localization of GRB000730B
  55. IPN localization of GRB000730B
  56. IPN localization of GRB000730
  57. GRB 990510: Possible detection of a host galaxy
  58. GRB 990510 Host Galaxy Discovery
  59. GRB 000727, optical observations
  60. IPN localization of GRB000727
  61. GRB 990705, HST/STIS observations of the host galaxy
  62. GRB 990712: Late time HST/STIS Observations
  63. GRB 991216, HST/STIS observations
  64. GRB000620, Radio Observations
  65. GRB981226, HST/STIS observations of the host galaxy
  66. GRB000630, optical observations
  67. GRB 000630: Detection of the Optical Afterglow
  68. GRB000630, Revised BVRI Field Photometry
  69. GRB000630, Optical Observations
  70. GRB000630, optical observations
  71. GRB000630, optical observations
  72. GRB000630, BVRI Field Photometry
  73. GRB000630, optical observations
  74. GRB000630, optical observations
  75. GRB000630: Optical observations
  76. GRB000630, Radio Observations
  77. possible optical counterpart of GRB 000630
  78. IPN triangulation of GRB000630
  79. GRB 000623, optical observations
  80. GRB 000620, optical observations
  81. GRB000418, HST/STIS Observations
  82. GRB990123: Late-time HST/STIS observations of the host
  83. GRB 990506, HST/STIS Observations of the Host Galaxy
  84. GRB000623
  85. GRB 000620: J-band observations
  86. GRB000620, optical observations
  87. GRB000615: H-band observations
  88. GRB990308, HST/STIS observations of the host galaxy
  89. GRB000620 - Optical observations
  90. GRB000620 Optical observations
  91. IPN annulus for GRB000620
  92. GRB000620: BeppoSAX WFC and GRBM detection
  93. GRB000615, Radio observations
  94. GRB000607, optical observations
  95. GRB 000615: NIR further observations
  96. GRB000620: refined BeppoSAX/WFC coordinates
  97. BeppoSAX ALERT: GRB000620
  98. GRB000620: BeppoSAX Alert
  99. GRB990123, HST/STIS observations of the host galaxy
  100. GRB000616 optical observations

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