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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. IPN triangulation of GRB001005
  2. HETE-2 48 hour Launch Delay
  3. GRB 000926 Chandra Observation
  4. IPN triangulation of GRB 001004
  5. Public availability of BeppoSAX data of GRB000926
  6. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  7. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  8. GRB000926 - Optical observations
  9. GRB000926 - Optical observations
  10. GRB 000926, Optical Decay
  11. GRB000911: VLT infrared observation
  12. GRB000926 - Optical observations
  13. GRB000926 - Optical observations
  14. GRB 000926: optical observations
  15. GRB 000926, Optical Observations
  16. GRB000926 - Optical observations
  17. GRB000911: optical VLT observations
  18. GRB000926 K'-band Observation
  19. GRB000926 : increasing optical decay slope
  20. GRB000926 optical observations
  21. GRB000926 - Optical observations
  22. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  23. J and K band observations of GRB 000926
  24. GRB000911 Optical Observations
  25. GRB 000926: Lightcurve Update and Predictions
  26. GRB 000926, optical observation by Oksanen (vsnet-grb)
  27. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  28. GRB000926: Optical observations
  29. CONCAM crude optical limits before and after GRB000926
  30. GRB 000926: Preliminary R-band Lightcurve
  31. GRB 000926 HST/Chandra TOO Status
  32. Spectroscopic Redshift of GRB 000926
  33. GRB 000926, Optical Observation
  34. GRB000926, radio observations
  35. GRB 000926: Optical candidate
  36. Optical candidate for GRB000926
  37. IPN triangulation of GRB000926
  38. IPN triangulation of GRB000926
  39. GRB 000911, BVRI field photometry
  40. GRB000911: Corrected coordinates
  41. GRB000911: Sub-millimeter observations
  42. IPN triangulation of GRB000925
  43. GRB000911: Optical Transient
  44. GRB000911, Radio and Optical observations
  45. GRB000911, Radio observations
  46. GRB000911: Optical observations
  47. IPN triangulation of GRB000911
  48. IPN triangulation of GRB000910
  49. False GRB alarm from RXTE/ASM on 8 Sept 2000
  50. GRB 000830: Optical observations
  51. GRB000830: Optical observations
  52. GRB000830, TNG B-band observations
  53. GRB000830, BVRI field photometry
  54. GRB000830: Optical observations
  55. GRB000210, Optical observations
  56. Chandra Position of GRB000210
  57. "Snapshot" afterglow IDs and GRB 000830
  58. GRB000830: Optical observations
  59. IPN triangulation of GRB000830
  60. HST/STIS observations of the host galaxy of GRB 980329
  61. HST/STIS observations of the chaotic environment of GRB 980613
  62. IPN localization of GRB000820
  63. SGR 1806-20 burst activity
  64. GRB000812, TNG R-band observations
  65. GRB000801 & GRB000730, Gamma Ray Observations
  66. GRB000730, Gamma Ray Observations
  67. GRB000812, Radio observations
  68. IPN localization of GRB000812
  69. IPN localization of GRB000811
  70. GRB000801, Gamma Ray Observations
  71. GRB000801, VLT-Antu R-band observations
  72. GRB000301C, UBVI optical observations
  73. GRB000801, Radio Observations
  74. GRB 991208 Host Galaxy Imaging
  75. Updated IPN coordinates for GRB000801
  76. IPN localization of GRB000801
  77. IPN localization of GRB000801
  78. IPN localization of GRB000730B
  79. IPN localization of GRB000730B
  80. IPN localization of GRB000730
  81. GRB 990510: Possible detection of a host galaxy
  82. GRB 990510 Host Galaxy Discovery
  83. GRB 000727, optical observations
  84. IPN localization of GRB000727
  85. GRB 990705, HST/STIS observations of the host galaxy
  86. GRB 990712: Late time HST/STIS Observations
  87. GRB 991216, HST/STIS observations
  88. GRB000620, Radio Observations
  89. GRB981226, HST/STIS observations of the host galaxy
  90. GRB000630, optical observations
  91. GRB 000630: Detection of the Optical Afterglow
  92. GRB000630, Revised BVRI Field Photometry
  93. GRB000630, Optical Observations
  94. GRB000630, optical observations
  95. GRB000630, optical observations
  96. GRB000630, BVRI Field Photometry
  97. GRB000630, optical observations
  98. GRB000630, optical observations
  99. GRB000630: Optical observations
  100. GRB000630, Radio Observations

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