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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 000418, Optical observation
  2. GRB000508B, optical photometry
  3. GRB000508B, BVR field photometry
  4. Possible GRB-related phenomenon
  5. RXTE/ASM and IPN localization of GRB 000508B
  6. GRB000424, UBVRI field photometry
  7. GRB 000424 Optical Observations
  8. GRB000418, UBVRI field photometry update
  9. The redshift of GRB 000418
  10. GRB000424, optical observations
  11. GRB 000429, optical observation
  12. GRB 000429, UBVRI field photometry
  13. IPN localization of GRB000429
  14. GRB 000418, UBVRI field photometry
  15. GRB000418, Radio detection
  16. GRB000418, K'-band photometry
  17. GRB 000418, Optical Observation
  18. GRB 000418, optical observation
  19. GRB000424 Optical Observations
  20. GRB 000418, Optical Observation
  21. GRB000424, optical observations
  22. GRB000424, optical observations
  23. GRB 000424, Optical Observations
  24. GRB 000418, Optical Observation
  25. GRB000418, near-infrared observations
  26. BeppoSAX GRB000424
  27. Correction to IPN error box for GRB000419
  28. IPN error box for GRB000418
  29. GRB000419 [IPN Position]
  30. GRB000416 Optical Observations
  31. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  32. GRB000416 BRJK observations
  33. 1SAXJ1715.0-7134 refined position
  34. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  35. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  36. Budget cuts in BeppoSAX operations: impact on GRB observations
  37. GRB 000408, optical observations
  38. Refined IPN error box for GRB000408
  39. GRB 991208, UBVRI field photometry
  40. GRB000301c results
  41. GRB000408: Optical CCD Observations from MIRO
  42. GRB000408, lotis optical observations
  43. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  44. GRB000408 [IPN Position]
  45. GRB000326 Optical Observations
  46. GRB000301C - Addendum to GCN 623
  47. GRB000301C - R magnitude lower limit
  48. GRB000326, Further VLA observations
  49. GRB 000323, optical observations
  50. GRB 000326: Optical Observations
  51. GRB000326, Radio observations
  52. GRB000326 [IPN Position]
  53. GRB 000307 optical observations
  54. GRB000323 [IPN Position]
  55. Single error box for GRB000315
  56. GRB000315 [IPN Positions]
  57. GRB000313, Radio observations
  58. GRB 000313 - optical transient in the BATSE error box
  59. GRB000301C - B and R photometry
  60. GRB000301C - R photometry
  61. GRB 000307, Optical Observations
  62. GRB 000307, BVRI Field Photometry
  63. GRB 000301C: Optical Spectrum and Redshift
  64. GRB 000301C: Optical Spectrum and Redshift
  65. GRB 000301C: A Precise Redshift Determination
  66. GRB 000301C, Optical Observation
  67. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  68. GRB 000301C: HST/STIS CCD Imaging of the field
  69. IPN error box for GRB000307
  70. GRB 000301c: K' observations
  71. GRB000301C, optical R-band observations
  72. GRB000301c - R photometry and nearby faint source confirmation
  73. GRB 000301C, Optical Observation
  74. GRB 000301c: K' observations
  75. GRB 000301C Optical Observations
  76. GRB 000301C: K' Observations
  77. GRB000301C OT candidate optical observations
  78. GRB000301C - Host galaxy not detected in R (?)
  79. Optical observations of GRB000301c
  80. GRB000301C, Radio observations
  81. GRB000301C, Radio observations
  82. GRB000301C optical observations
  83. GRB000301C, near-infrared observations (JHK' imaging)
  84. GRB 000301c near-IR observations
  85. GRB 000301C, Optical Color
  86. GRB000301C, Optical Spectroscopy
  87. GRB 000301C, UBVRI field photometry
  88. GRB 000301C, Optical Observation
  89. GRB000301C, optical observations
  90. GRB000301C 250 GHz detection
  91. GRB 000301C R-band observation
  92. GRB 000301C, Optical Observation
  93. GRB000301C, near-infrared observations (JHK' photometry)
  94. GRB 000301C: OT confirmed
  95. GRB000301c optical observations
  96. GRB 000301A, Radio Observations
  97. GRB000301C, optical observations
  98. GRB000301c, near-infrared observations
  99. GRB000301C
  100. GRB 000301C : Optical Candidate

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