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

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