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

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