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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"

25040 results found.

  1. GRB001018, Gamma Ray Observations
  2. IPN TRIANGULATION OF GRB001019
  3. IPN TRIANGULATION OF GRB001018
  4. IPN TRIANGULATION OF GRB 001017
  5. V,R,I band observations of GRB000926
  6. HETE positions added to GCN
  7. GRB000926 - Amateur Optical Observations
  8. CONCAM null result on GRB001005
  9. IPN triangulation of GRB001005
  10. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  11. GRB000926 - Optical observations
  12. GRB000926 - Optical observations
  13. GRB 000926, Optical Decay
  14. GRB000911: VLT infrared observation
  15. GRB 000926, Optical Observations
  16. GRB000926 K'-band Observation
  17. J and K band observations of GRB 000926
  18. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  19. CONCAM crude optical limits before and after GRB000926
  20. GRB 000926: Preliminary R-band Lightcurve
  21. Spectroscopic Redshift of GRB 000926
  22. GRB 000926: Optical candidate
  23. Optical candidate for GRB000926
  24. GRB 000911, BVRI field photometry
  25. GRB000911, Radio and Optical observations
  26. GRB000911: Optical observations
  27. GRB000830, BVRI field photometry
  28. GRB000210, Optical observations
  29. "Snapshot" afterglow IDs and GRB 000830
  30. GRB000730, Gamma Ray Observations
  31. GRB000812, Radio observations
  32. GRB000801, Gamma Ray Observations
  33. GRB000801, VLT-Antu R-band observations
  34. GRB 991208 Host Galaxy Imaging
  35. IPN localization of GRB000730B
  36. GRB 990510: Possible detection of a host galaxy
  37. GRB 990510 Host Galaxy Discovery
  38. IPN localization of GRB000727
  39. GRB 990712: Late time HST/STIS Observations
  40. GRB 991216, HST/STIS observations
  41. GRB000620, Radio Observations
  42. GRB000630, optical observations
  43. GRB000630, Revised BVRI Field Photometry
  44. GRB000630, Optical Observations
  45. GRB000630, optical observations
  46. GRB000630, optical observations
  47. GRB000630, BVRI Field Photometry
  48. GRB000630, optical observations
  49. GRB000630: Optical observations
  50. GRB000630, Radio Observations
  51. possible optical counterpart of GRB 000630
  52. GRB 000620, optical observations
  53. GRB000418, HST/STIS Observations
  54. GRB990123: Late-time HST/STIS observations of the host
  55. GRB000620, optical observations
  56. GRB000615: H-band observations
  57. GRB990308, HST/STIS observations of the host galaxy
  58. GRB000620 - Optical observations
  59. GRB000620 Optical observations
  60. GRB000620: BeppoSAX WFC and GRBM detection
  61. GRB000607, optical observations
  62. GRB 000615: NIR further observations
  63. GRB990123, HST/STIS observations of the host galaxy
  64. GRB000616 optical observations
  65. GRB 000615, near-infrared observations
  66. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  67. GRB000615, further R-band photometry
  68. GRB 000615: NIR observations
  69. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  70. GRB000615, R-band photometry
  71. The Hosts of GRB 980703 and GRB 971214
  72. GRB 000301C: Further Late-Time HST/STIS observations
  73. GRB000528: follow-up X-ray measurements and update of IPN annulus
  74. GRB980519, HST/STIS observations of the host galaxy
  75. GRB000604 optical non-detection
  76. GRB000604 - Optical observations
  77. GRB000604, optical observations
  78. GRB000528, optical observations at ESO
  79. GRB 000604 optical observations
  80. GRB 000418: Detection of the Host Galaxy
  81. GRB000604, optical observations, comparison with DPOSS
  82. GRB000528, Radio Observations
  83. X-ray Afterglow of GRB 000529
  84. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  85. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  86. GRB 000528 - WFC measurements
  87. GRB000519, BVRI field photometry
  88. IPN triangulation of GRB000519
  89. GRB000508B, optical photometry
  90. GRB000508B, BVR field photometry
  91. Possible GRB-related phenomenon
  92. RXTE/ASM and IPN localization of GRB 000508B
  93. GRB000424, UBVRI field photometry
  94. GRB000418, UBVRI field photometry update
  95. GRB000424, optical observations
  96. GRB 000429, optical observation
  97. GRB 000429, UBVRI field photometry
  98. GRB 000418, UBVRI field photometry
  99. GRB 000418, optical observation
  100. GRB 000418, Optical Observation

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