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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"

28057 results found.

  1. GRB 001109: deep JHK upper limits
  2. GRB 001109 X-ray afterglow with BeppoSAX
  3. CORRECTION to XMM-Newton observation of GRB001025
  4. GRB001109, Radio observations
  5. GRB001105 BVRI field photometry correction
  6. GRB001105, BVRI field photometry
  7. IPN TRIANGULATION OF GRB001105
  8. GRB 001025B, Optical obervations
  9. GRB 991208: HST Imaging of the Host Galaxy
  10. GRB 001025B, I-band observations
  11. XMM-Newton observation of GRB001025
  12. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  13. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  14. GRB001007: Optical observations
  15. ASM Localization of GRB 001025
  16. GRB001007, Radio observations
  17. GRB 001018, Possible Radio Afterglow
  18. GRB001018, Gamma Ray Observations
  19. IPN TRIANGULATION OF GRB001019
  20. IPN TRIANGULATION OF GRB001018
  21. IPN TRIANGULATION OF GRB 001017
  22. V,R,I band observations of GRB000926
  23. HETE positions added to GCN
  24. GRB000926 - Amateur Optical Observations
  25. CONCAM null result on GRB001005
  26. IPN triangulation of GRB001005
  27. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  28. GRB000926 - Optical observations
  29. GRB000926 - Optical observations
  30. GRB 000926, Optical Decay
  31. GRB000911: VLT infrared observation
  32. GRB 000926, Optical Observations
  33. GRB000926 K'-band Observation
  34. J and K band observations of GRB 000926
  35. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  36. CONCAM crude optical limits before and after GRB000926
  37. GRB 000926: Preliminary R-band Lightcurve
  38. Spectroscopic Redshift of GRB 000926
  39. GRB 000926: Optical candidate
  40. Optical candidate for GRB000926
  41. GRB 000911, BVRI field photometry
  42. GRB000911, Radio and Optical observations
  43. GRB000911: Optical observations
  44. GRB000830, BVRI field photometry
  45. GRB000210, Optical observations
  46. "Snapshot" afterglow IDs and GRB 000830
  47. GRB000730, Gamma Ray Observations
  48. GRB000812, Radio observations
  49. GRB000801, Gamma Ray Observations
  50. GRB000801, VLT-Antu R-band observations
  51. GRB 991208 Host Galaxy Imaging
  52. IPN localization of GRB000730B
  53. GRB 990510: Possible detection of a host galaxy
  54. GRB 990510 Host Galaxy Discovery
  55. IPN localization of GRB000727
  56. GRB 990712: Late time HST/STIS Observations
  57. GRB 991216, HST/STIS observations
  58. GRB000620, Radio Observations
  59. GRB000630, optical observations
  60. GRB000630, Revised BVRI Field Photometry
  61. GRB000630, Optical Observations
  62. GRB000630, optical observations
  63. GRB000630, optical observations
  64. GRB000630, BVRI Field Photometry
  65. GRB000630, optical observations
  66. GRB000630: Optical observations
  67. GRB000630, Radio Observations
  68. possible optical counterpart of GRB 000630
  69. GRB 000620, optical observations
  70. GRB000418, HST/STIS Observations
  71. GRB990123: Late-time HST/STIS observations of the host
  72. GRB000620, optical observations
  73. GRB000615: H-band observations
  74. GRB990308, HST/STIS observations of the host galaxy
  75. GRB000620 - Optical observations
  76. GRB000620 Optical observations
  77. GRB000620: BeppoSAX WFC and GRBM detection
  78. GRB000607, optical observations
  79. GRB 000615: NIR further observations
  80. GRB990123, HST/STIS observations of the host galaxy
  81. GRB000616 optical observations
  82. GRB 000615, near-infrared observations
  83. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  84. GRB000615, further R-band photometry
  85. GRB 000615: NIR observations
  86. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  87. GRB000615, R-band photometry
  88. The Hosts of GRB 980703 and GRB 971214
  89. GRB 000301C: Further Late-Time HST/STIS observations
  90. GRB000528: follow-up X-ray measurements and update of IPN annulus
  91. GRB980519, HST/STIS observations of the host galaxy
  92. GRB000604 optical non-detection
  93. GRB000604 - Optical observations
  94. GRB000604, optical observations
  95. GRB000528, optical observations at ESO
  96. GRB 000604 optical observations
  97. GRB 000418: Detection of the Host Galaxy
  98. GRB000604, optical observations, comparison with DPOSS
  99. GRB000528, Radio Observations
  100. X-ray Afterglow of GRB 000529

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