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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. GRB000313, Radio observations
  2. GRB 000313 - optical transient in the BATSE error box
  3. GRB000301C - B and R photometry
  4. GRB000301C - R photometry
  5. GRB 000307, Optical Observations
  6. GRB 000307, BVRI Field Photometry
  7. GRB 000301C: Optical Spectrum and Redshift
  8. GRB 000301C: Optical Spectrum and Redshift
  9. GRB 000301C: A Precise Redshift Determination
  10. GRB 000301C, Optical Observation
  11. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  12. GRB 000301C: HST/STIS CCD Imaging of the field
  13. IPN error box for GRB000307
  14. GRB 000301c: K' observations
  15. GRB000301C, optical R-band observations
  16. GRB000301c - R photometry and nearby faint source confirmation
  17. GRB 000301C, Optical Observation
  18. GRB 000301c: K' observations
  19. GRB 000301C Optical Observations
  20. GRB 000301C: K' Observations
  21. GRB000301C OT candidate optical observations
  22. GRB000301C - Host galaxy not detected in R (?)
  23. Optical observations of GRB000301c
  24. GRB000301C, Radio observations
  25. GRB000301C, Radio observations
  26. GRB000301C optical observations
  27. GRB000301C, near-infrared observations (JHK' imaging)
  28. GRB 000301c near-IR observations
  29. GRB 000301C, Optical Color
  30. GRB000301C, Optical Spectroscopy
  31. GRB 000301C, UBVRI field photometry
  32. GRB 000301C, Optical Observation
  33. GRB000301C, optical observations
  34. GRB000301C 250 GHz detection
  35. GRB 000301C R-band observation
  36. GRB 000301C, Optical Observation
  37. GRB000301C, near-infrared observations (JHK' photometry)
  38. GRB 000301C: OT confirmed
  39. GRB000301c optical observations
  40. GRB 000301A, Radio Observations
  41. GRB000301C, optical observations
  42. GRB000301c, near-infrared observations
  43. GRB000301C
  44. GRB 000301C : Optical Candidate
  45. Radio observations of the error box of GRB000301A
  46. GRB000301C: RXTE/ASM and IPN localizations
  47. GRB000301A [IPN Position]
  48. GRB000226 [IPN Position]
  49. HST Observations of GRB 990712
  50. GRB 000214 near-IR observations
  51. GRB 000115 Optical observations
  52. GRB 000214, Radio Observations
  53. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  54. GRB000210, Radio Observations
  55. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  56. GRB 000115, BVRI field photometry
  57. GRB000214: BeppoSAX GRBM and WFC Detection
  58. IPN annulus for GRB000214
  59. BATSE GRB trigger criterion changed
  60. Optical observations of GRB000210
  61. GRB000210 X-ray afterglow
  62. GRB000214: X-ray afterglow candidate
  63. GRB000214 refined BeppoSAX-WFC position
  64. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  65. GRB 000210: BATSE Observations
  66. Correction to Chandra Position of GRB000210 afterglow
  67. Optical observations of the Chandra X-ray source for GRB000210
  68. GRB000210, Radio Observations
  69. Optical candidate for GRB000210
  70. Chandra Observations of GRB000210 X-ray Afterglow
  71. IPN triangulation of GRB000210
  72. GRB000210: possible afterglow detection with BeppoSAX NFI
  73. GRB000201, Radio Observations
  74. GRB000210: BeppoSAX GRBM and WFC Detection
  75. SAX_WFC_GRB_NOTICE
  76. SAX_WFC_GRB_NOTICE
  77. Optical observations of GRB000131
  78. GRB000201 Optical Observations
  79. GRB 000201: TAROT optical observations
  80. GRB 000131 Optical Observations
  81. GRB000126 Optical Observations
  82. BATSE GRB trigger criteria changed
  83. GRB 991208, radio observations
  84. BATSE+IPN location of GRB000131
  85. IPN localization of GRB000131
  86. GRB 000126, optical observations
  87. GRB000126, optical observations
  88. BATSE location of GRB000126
  89. IPN localization of GRB000126
  90. GRB 000115 Optical observations
  91. BATSE Observations of GRB000115
  92. Correction to GCN 520 (IPN annulus for GRB000115)
  93. IPN annulus for GRB000115
  94. Second RXTE Observation of GRB 000115
  95. GRB991216, UBVRIJHK field photometry
  96. GRB991216 late optical observation
  97. Single IPN error box for GRB991229
  98. GCN resumes full operations
  99. GRB 991216 VLBA Observations
  100. BEPPOSAX GRBM Localization of GRB991226

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