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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"

28055 results found.

  1. CORRECTION to XMM-Newton observation of GRB001025
  2. GRB001109, Radio observations
  3. GRB001105 BVRI field photometry correction
  4. GRB001105, BVRI field photometry
  5. IPN TRIANGULATION OF GRB001105
  6. GRB 001025B, Optical obervations
  7. GRB 991208: HST Imaging of the Host Galaxy
  8. GRB 001025B, I-band observations
  9. XMM-Newton observation of GRB001025
  10. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  11. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  12. GRB001007: Optical observations
  13. ASM Localization of GRB 001025
  14. GRB001007, Radio observations
  15. GRB 001018, Possible Radio Afterglow
  16. GRB001018, Gamma Ray Observations
  17. IPN TRIANGULATION OF GRB001019
  18. IPN TRIANGULATION OF GRB001018
  19. IPN TRIANGULATION OF GRB 001017
  20. V,R,I band observations of GRB000926
  21. HETE positions added to GCN
  22. GRB000926 - Amateur Optical Observations
  23. CONCAM null result on GRB001005
  24. IPN triangulation of GRB001005
  25. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  26. GRB000926 - Optical observations
  27. GRB000926 - Optical observations
  28. GRB 000926, Optical Decay
  29. GRB000911: VLT infrared observation
  30. GRB 000926, Optical Observations
  31. GRB000926 K'-band Observation
  32. J and K band observations of GRB 000926
  33. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  34. CONCAM crude optical limits before and after GRB000926
  35. GRB 000926: Preliminary R-band Lightcurve
  36. Spectroscopic Redshift of GRB 000926
  37. GRB 000926: Optical candidate
  38. Optical candidate for GRB000926
  39. GRB 000911, BVRI field photometry
  40. GRB000911, Radio and Optical observations
  41. GRB000911: Optical observations
  42. GRB000830, BVRI field photometry
  43. GRB000210, Optical observations
  44. "Snapshot" afterglow IDs and GRB 000830
  45. GRB000730, Gamma Ray Observations
  46. GRB000812, Radio observations
  47. GRB000801, Gamma Ray Observations
  48. GRB000801, VLT-Antu R-band observations
  49. GRB 991208 Host Galaxy Imaging
  50. IPN localization of GRB000730B
  51. GRB 990510: Possible detection of a host galaxy
  52. GRB 990510 Host Galaxy Discovery
  53. IPN localization of GRB000727
  54. GRB 990712: Late time HST/STIS Observations
  55. GRB 991216, HST/STIS observations
  56. GRB000620, Radio Observations
  57. GRB000630, optical observations
  58. GRB000630, Revised BVRI Field Photometry
  59. GRB000630, Optical Observations
  60. GRB000630, optical observations
  61. GRB000630, optical observations
  62. GRB000630, BVRI Field Photometry
  63. GRB000630, optical observations
  64. GRB000630: Optical observations
  65. GRB000630, Radio Observations
  66. possible optical counterpart of GRB 000630
  67. GRB 000620, optical observations
  68. GRB000418, HST/STIS Observations
  69. GRB990123: Late-time HST/STIS observations of the host
  70. GRB000620, optical observations
  71. GRB000615: H-band observations
  72. GRB990308, HST/STIS observations of the host galaxy
  73. GRB000620 - Optical observations
  74. GRB000620 Optical observations
  75. GRB000620: BeppoSAX WFC and GRBM detection
  76. GRB000607, optical observations
  77. GRB 000615: NIR further observations
  78. GRB990123, HST/STIS observations of the host galaxy
  79. GRB000616 optical observations
  80. GRB 000615, near-infrared observations
  81. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  82. GRB000615, further R-band photometry
  83. GRB 000615: NIR observations
  84. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  85. GRB000615, R-band photometry
  86. The Hosts of GRB 980703 and GRB 971214
  87. GRB 000301C: Further Late-Time HST/STIS observations
  88. GRB000528: follow-up X-ray measurements and update of IPN annulus
  89. GRB980519, HST/STIS observations of the host galaxy
  90. GRB000604 optical non-detection
  91. GRB000604 - Optical observations
  92. GRB000604, optical observations
  93. GRB000528, optical observations at ESO
  94. GRB 000604 optical observations
  95. GRB 000418: Detection of the Host Galaxy
  96. GRB000604, optical observations, comparison with DPOSS
  97. GRB000528, Radio Observations
  98. X-ray Afterglow of GRB 000529
  99. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  100. GRB000528: BeppoSAX NFI follow-up preliminary analysis

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