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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 990506, HST/STIS Observations of the Host Galaxy
  2. GRB000623
  3. GRB 000620: J-band observations
  4. GRB000620, optical observations
  5. GRB000615: H-band observations
  6. GRB990308, HST/STIS observations of the host galaxy
  7. GRB000620 - Optical observations
  8. GRB000620 Optical observations
  9. IPN annulus for GRB000620
  10. GRB000620: BeppoSAX WFC and GRBM detection
  11. GRB000615, Radio observations
  12. GRB000607, optical observations
  13. GRB 000615: NIR further observations
  14. GRB000620: refined BeppoSAX/WFC coordinates
  15. BeppoSAX ALERT: GRB000620
  16. GRB000620: BeppoSAX Alert
  17. GRB990123, HST/STIS observations of the host galaxy
  18. GRB000616 optical observations
  19. GRB 000615, near-infrared observations
  20. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  21. GRB000616 [IPN Position]
  22. GRB000615B [IPN Position]
  23. GRB000615, further R-band photometry
  24. GRB 000615: NIR observations
  25. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  26. GRB000615, R-band photometry
  27. GRB000615: BeppoSAX refined coordinates
  28. GRB980425, HST/STIS observations of the host galaxy
  29. GRB000615: BeppoSAX GRB Alert
  30. The Hosts of GRB 980703 and GRB 971214
  31. GRB 000301C: Further Late-Time HST/STIS observations
  32. GRB000528: follow-up X-ray measurements and update of IPN annulus
  33. Optical Follow-up of GRB000529 Error Box
  34. GRB980519, HST/STIS observations of the host galaxy
  35. GRB000607, Radio Observations
  36. BeppoSAX X-ray transient/possible GRB000608
  37. GRB000604 optical non-detection
  38. GRB000604 - Optical observations
  39. GRB000607, A SHORT, HARD BURST
  40. GRB000604, optical observations
  41. GRB000528, optical observations at ESO
  42. GRB 000604 optical observations
  43. GRB 000418: Detection of the Host Galaxy
  44. GRB000604, optical observations, comparison with DPOSS
  45. GRB000604 [IPN Position]
  46. GRB000528, Radio Observations
  47. X-ray Afterglow of GRB 000529
  48. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  49. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  50. GRB000529: Optical Observations
  51. IPN localization and time history of GRB000528
  52. New IPN localization of GRB000529
  53. GRB000519: Optical observations
  54. IPN localization of GRB000529
  55. GRB 000528 - WFC measurements
  56. GRB000529: BeppoSAX WFC position
  57. GRB000528: BeppoSAX GRBM observations
  58. GRB 000528 Optical Observations
  59. GRB000519, BVRI field photometry
  60. IPN triangulation of GRB000519
  61. IPN triangulation of GRB000516
  62. Re: GRB000508B : Optical observations
  63. GRB 000418, Optical observation
  64. GRB000508B, optical photometry
  65. GRB000508B, BVR field photometry
  66. Possible GRB-related phenomenon
  67. RXTE/ASM and IPN localization of GRB 000508B
  68. GRB000424, UBVRI field photometry
  69. GRB 000424 Optical Observations
  70. GRB000418, UBVRI field photometry update
  71. The redshift of GRB 000418
  72. GRB000424, optical observations
  73. GRB 000429, optical observation
  74. GRB 000429, UBVRI field photometry
  75. IPN localization of GRB000429
  76. GRB 000418, UBVRI field photometry
  77. GRB000418, Radio detection
  78. GRB000418, K'-band photometry
  79. GRB 000418, Optical Observation
  80. GRB 000418, optical observation
  81. GRB000424 Optical Observations
  82. GRB 000418, Optical Observation
  83. GRB000424, optical observations
  84. GRB000424, optical observations
  85. GRB 000424, Optical Observations
  86. GRB 000418, Optical Observation
  87. GRB000418, near-infrared observations
  88. BeppoSAX GRB000424
  89. Correction to IPN error box for GRB000419
  90. IPN error box for GRB000418
  91. GRB000419 [IPN Position]
  92. GRB000416 Optical Observations
  93. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  94. GRB000416 BRJK observations
  95. 1SAXJ1715.0-7134 refined position
  96. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  97. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  98. Budget cuts in BeppoSAX operations: impact on GRB observations
  99. GRB 000408, optical observations
  100. Refined IPN error box for GRB000408

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