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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"

28045 results found.

  1. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  2. GRB001007: Optical observations
  3. ASM Localization of GRB 001025
  4. GRB001007, Radio observations
  5. GRB 001018, Possible Radio Afterglow
  6. GRB001018, Gamma Ray Observations
  7. IPN TRIANGULATION OF GRB001019
  8. IPN TRIANGULATION OF GRB001018
  9. IPN TRIANGULATION OF GRB 001017
  10. V,R,I band observations of GRB000926
  11. HETE positions added to GCN
  12. GRB000926 - Amateur Optical Observations
  13. CONCAM null result on GRB001005
  14. IPN triangulation of GRB001005
  15. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  16. GRB000926 - Optical observations
  17. GRB000926 - Optical observations
  18. GRB 000926, Optical Decay
  19. GRB000911: VLT infrared observation
  20. GRB 000926, Optical Observations
  21. GRB000926 K'-band Observation
  22. J and K band observations of GRB 000926
  23. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  24. CONCAM crude optical limits before and after GRB000926
  25. GRB 000926: Preliminary R-band Lightcurve
  26. Spectroscopic Redshift of GRB 000926
  27. GRB 000926: Optical candidate
  28. Optical candidate for GRB000926
  29. GRB 000911, BVRI field photometry
  30. GRB000911, Radio and Optical observations
  31. GRB000911: Optical observations
  32. GRB000830, BVRI field photometry
  33. GRB000210, Optical observations
  34. "Snapshot" afterglow IDs and GRB 000830
  35. GRB000730, Gamma Ray Observations
  36. GRB000812, Radio observations
  37. GRB000801, Gamma Ray Observations
  38. GRB000801, VLT-Antu R-band observations
  39. GRB 991208 Host Galaxy Imaging
  40. IPN localization of GRB000730B
  41. GRB 990510: Possible detection of a host galaxy
  42. GRB 990510 Host Galaxy Discovery
  43. IPN localization of GRB000727
  44. GRB 990712: Late time HST/STIS Observations
  45. GRB 991216, HST/STIS observations
  46. GRB000620, Radio Observations
  47. GRB000630, optical observations
  48. GRB000630, Revised BVRI Field Photometry
  49. GRB000630, Optical Observations
  50. GRB000630, optical observations
  51. GRB000630, optical observations
  52. GRB000630, BVRI Field Photometry
  53. GRB000630, optical observations
  54. GRB000630: Optical observations
  55. GRB000630, Radio Observations
  56. possible optical counterpart of GRB 000630
  57. GRB 000620, optical observations
  58. GRB000418, HST/STIS Observations
  59. GRB990123: Late-time HST/STIS observations of the host
  60. GRB000620, optical observations
  61. GRB000615: H-band observations
  62. GRB990308, HST/STIS observations of the host galaxy
  63. GRB000620 - Optical observations
  64. GRB000620 Optical observations
  65. GRB000620: BeppoSAX WFC and GRBM detection
  66. GRB000607, optical observations
  67. GRB 000615: NIR further observations
  68. GRB990123, HST/STIS observations of the host galaxy
  69. GRB000616 optical observations
  70. GRB 000615, near-infrared observations
  71. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  72. GRB000615, further R-band photometry
  73. GRB 000615: NIR observations
  74. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  75. GRB000615, R-band photometry
  76. The Hosts of GRB 980703 and GRB 971214
  77. GRB 000301C: Further Late-Time HST/STIS observations
  78. GRB000528: follow-up X-ray measurements and update of IPN annulus
  79. GRB980519, HST/STIS observations of the host galaxy
  80. GRB000604 optical non-detection
  81. GRB000604 - Optical observations
  82. GRB000604, optical observations
  83. GRB000528, optical observations at ESO
  84. GRB 000604 optical observations
  85. GRB 000418: Detection of the Host Galaxy
  86. GRB000604, optical observations, comparison with DPOSS
  87. GRB000528, Radio Observations
  88. X-ray Afterglow of GRB 000529
  89. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  90. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  91. GRB 000528 - WFC measurements
  92. GRB000519, BVRI field photometry
  93. IPN triangulation of GRB000519
  94. GRB000508B, optical photometry
  95. GRB000508B, BVR field photometry
  96. Possible GRB-related phenomenon
  97. RXTE/ASM and IPN localization of GRB 000508B
  98. GRB000424, UBVRI field photometry
  99. GRB000418, UBVRI field photometry update
  100. GRB000424, optical observations

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