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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').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

26498 results found.

  1. The Likely Optical/Infrared Afterglow of GRB 001011
  2. HETE positions added to GCN
  3. GRB001011 BeppoSAX/WFC refined position
  4. GRB 001007, BVR-band observations
  5. GRB000926 - Amateur Optical Observations
  6. GRB001007: Optical observations
  7. CONCAM null result on GRB001005
  8. IPN triangulation of GRB001007
  9. HETE-2 Launches Successfully
  10. HETE-2 48 hour Launch Delay
  11. GRB 000926 Chandra Observation
  12. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  13. GRB000926 - Optical observations
  14. GRB000926 - Optical observations
  15. GRB 000926, Optical Decay
  16. GRB 000926, Optical Observations
  17. GRB000926 K'-band Observation
  18. J and K band observations of GRB 000926
  19. GRB 000926, optical observation by Oksanen (vsnet-grb)
  20. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  21. CONCAM crude optical limits before and after GRB000926
  22. Spectroscopic Redshift of GRB 000926
  23. GRB 000926: Optical candidate
  24. Optical candidate for GRB000926
  25. IPN triangulation of GRB000926
  26. GRB 000911, BVRI field photometry
  27. IPN triangulation of GRB000925
  28. GRB000911, Radio and Optical observations
  29. GRB000911: Optical observations
  30. IPN triangulation of GRB000911
  31. IPN triangulation of GRB000910
  32. GRB000830, BVRI field photometry
  33. IPN triangulation of GRB000830
  34. HST/STIS observations of the host galaxy of GRB 980329
  35. IPN localization of GRB000820
  36. SGR 1806-20 burst activity
  37. GRB000801 & GRB000730, Gamma Ray Observations
  38. GRB000730, Gamma Ray Observations
  39. IPN localization of GRB000812
  40. IPN localization of GRB000811
  41. GRB000801, Gamma Ray Observations
  42. GRB000801, VLT-Antu R-band observations
  43. GRB 991208 Host Galaxy Imaging
  44. IPN localization of GRB000801
  45. IPN localization of GRB000730B
  46. IPN localization of GRB000730B
  47. IPN localization of GRB000730
  48. GRB 990510: Possible detection of a host galaxy
  49. GRB 990510 Host Galaxy Discovery
  50. IPN localization of GRB000727
  51. GRB 990705, HST/STIS observations of the host galaxy
  52. GRB 990712: Late time HST/STIS Observations
  53. GRB 991216, HST/STIS observations
  54. GRB000630, optical observations
  55. GRB000630, Revised BVRI Field Photometry
  56. GRB000630, Optical Observations
  57. GRB000630, optical observations
  58. GRB000630, optical observations
  59. GRB000630, BVRI Field Photometry
  60. GRB000630, optical observations
  61. GRB000630: Optical observations
  62. possible optical counterpart of GRB 000630
  63. IPN triangulation of GRB000630
  64. GRB 000620, optical observations
  65. GRB000418, HST/STIS Observations
  66. GRB990123: Late-time HST/STIS observations of the host
  67. GRB 990506, HST/STIS Observations of the Host Galaxy
  68. GRB000623
  69. GRB 000620: J-band observations
  70. GRB000620, optical observations
  71. GRB990308, HST/STIS observations of the host galaxy
  72. GRB000620 - Optical observations
  73. GRB000620 Optical observations
  74. GRB000620: BeppoSAX WFC and GRBM detection
  75. GRB000607, optical observations
  76. GRB 000615: NIR further observations
  77. GRB990123, HST/STIS observations of the host galaxy
  78. GRB000616 optical observations
  79. GRB 000615, near-infrared observations
  80. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  81. GRB000616 [IPN Position]
  82. GRB000615B [IPN Position]
  83. GRB000615, further R-band photometry
  84. GRB 000615: NIR observations
  85. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  86. GRB000615, R-band photometry
  87. GRB000615: BeppoSAX refined coordinates
  88. GRB980425, HST/STIS observations of the host galaxy
  89. GRB 000301C: Further Late-Time HST/STIS observations
  90. GRB000528: follow-up X-ray measurements and update of IPN annulus
  91. BeppoSAX X-ray transient/possible GRB000608
  92. GRB000604 - Optical observations
  93. GRB000607, A SHORT, HARD BURST
  94. GRB000604, optical observations
  95. GRB000528, optical observations at ESO
  96. GRB 000418: Detection of the Host Galaxy
  97. GRB000604, optical observations, comparison with DPOSS
  98. GRB000604 [IPN Position]
  99. GRB000528, Radio Observations
  100. X-ray Afterglow of GRB 000529

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