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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"

21668 results found.

  1. IPN triangulation of GRB001204 (short/hard)
  2. GRB 001105, further optical observations
  3. GRB001120, optical observations
  4. WSRT 4.8 GHz observations of GRB001109
  5. IPN triangulation of GRB001120
  6. Optical/NIR observations of GRB001109
  7. GRB 001109: deep JHK upper limits
  8. GRB 001109 X-ray afterglow with BeppoSAX
  9. CORRECTION to XMM-Newton observation of GRB001025
  10. GRB001109, Radio observations
  11. GRB001105 BVRI field photometry correction
  12. GRB001105, BVRI field photometry
  13. IPN TRIANGULATION OF GRB001105
  14. GRB 001025B, Optical obervations
  15. GRB 991208: HST Imaging of the Host Galaxy
  16. GRB 001025B, I-band observations
  17. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  18. IPN triangulation of GRB001025
  19. GRB001007: Optical observations
  20. ASM Localization of GRB 001025
  21. GRB001007, Radio observations
  22. IPN TRIANGULATION OF GRB001020
  23. IPN TRIANGULATION OF GRB001019
  24. IPN TRIANGULATION OF GRB001018
  25. IPN TRIANGULATION OF GRB 001017
  26. V,R,I band observations of GRB000926
  27. HETE positions added to GCN
  28. GRB000926 - Amateur Optical Observations
  29. GRB001007: Optical observations
  30. CONCAM null result on GRB001005
  31. IPN triangulation of GRB001007
  32. IPN triangulation of GRB001005
  33. GRB 000926 Chandra Observation
  34. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  35. GRB000926 - Optical observations
  36. GRB000926 - Optical observations
  37. GRB 000926, Optical Observations
  38. GRB000926 K'-band Observation
  39. J and K band observations of GRB 000926
  40. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  41. CONCAM crude optical limits before and after GRB000926
  42. GRB 000926: Optical candidate
  43. Optical candidate for GRB000926
  44. IPN triangulation of GRB000926
  45. GRB 000911, BVRI field photometry
  46. IPN triangulation of GRB000925
  47. GRB000911, Radio and Optical observations
  48. GRB000911, Radio observations
  49. GRB000911: Optical observations
  50. IPN triangulation of GRB000911
  51. IPN triangulation of GRB000910
  52. GRB 000830: Optical observations
  53. GRB000830: Optical observations
  54. GRB000830, TNG B-band observations
  55. GRB000830, BVRI field photometry
  56. GRB000830: Optical observations
  57. GRB000830: Optical observations
  58. IPN triangulation of GRB000830
  59. IPN localization of GRB000820
  60. GRB000812, TNG R-band observations
  61. IPN localization of GRB000812
  62. IPN localization of GRB000811
  63. GRB000801, VLT-Antu R-band observations
  64. GRB 991208 Host Galaxy Imaging
  65. IPN localization of GRB000801
  66. IPN localization of GRB000730B
  67. IPN localization of GRB000730B
  68. IPN localization of GRB000730
  69. GRB 990510: Possible detection of a host galaxy
  70. GRB 990510 Host Galaxy Discovery
  71. IPN localization of GRB000727
  72. GRB 990712: Late time HST/STIS Observations
  73. GRB 991216, HST/STIS observations
  74. GRB000630, optical observations
  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. possible optical counterpart of GRB 000630
  83. IPN triangulation of GRB000630
  84. GRB 000620, optical observations
  85. GRB000418, HST/STIS Observations
  86. GRB990123: Late-time HST/STIS observations of the host
  87. GRB000623
  88. GRB000620, optical observations
  89. GRB000615: H-band observations
  90. GRB000620 - Optical observations
  91. GRB000620 Optical observations
  92. IPN annulus for GRB000620
  93. GRB000620: BeppoSAX WFC and GRBM detection
  94. GRB000607, optical observations
  95. GRB 000615: NIR further observations
  96. GRB990123, HST/STIS observations of the host galaxy
  97. GRB000616 optical observations
  98. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  99. GRB000616 [IPN Position]
  100. GRB000615B [IPN Position]

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