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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"

28051 results found.

  1. IPN TRIANGULATION OF GRB001105
  2. GRB 001025B, Optical obervations
  3. GRB 991208: HST Imaging of the Host Galaxy
  4. GRB 001025B, I-band observations
  5. XMM-Newton observation of GRB001025
  6. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  7. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  8. GRB001007: Optical observations
  9. ASM Localization of GRB 001025
  10. GRB001007, Radio observations
  11. GRB 001018, Possible Radio Afterglow
  12. GRB001018, Gamma Ray Observations
  13. IPN TRIANGULATION OF GRB001019
  14. IPN TRIANGULATION OF GRB001018
  15. IPN TRIANGULATION OF GRB 001017
  16. V,R,I band observations of GRB000926
  17. HETE positions added to GCN
  18. GRB000926 - Amateur Optical Observations
  19. CONCAM null result on GRB001005
  20. IPN triangulation of GRB001005
  21. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  22. GRB000926 - Optical observations
  23. GRB000926 - Optical observations
  24. GRB 000926, Optical Decay
  25. GRB000911: VLT infrared observation
  26. GRB 000926, Optical Observations
  27. GRB000926 K'-band Observation
  28. J and K band observations of GRB 000926
  29. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  30. CONCAM crude optical limits before and after GRB000926
  31. GRB 000926: Preliminary R-band Lightcurve
  32. Spectroscopic Redshift of GRB 000926
  33. GRB 000926: Optical candidate
  34. Optical candidate for GRB000926
  35. GRB 000911, BVRI field photometry
  36. GRB000911, Radio and Optical observations
  37. GRB000911: Optical observations
  38. GRB000830, BVRI field photometry
  39. GRB000210, Optical observations
  40. "Snapshot" afterglow IDs and GRB 000830
  41. GRB000730, Gamma Ray Observations
  42. GRB000812, Radio observations
  43. GRB000801, Gamma Ray Observations
  44. GRB000801, VLT-Antu R-band observations
  45. GRB 991208 Host Galaxy Imaging
  46. IPN localization of GRB000730B
  47. GRB 990510: Possible detection of a host galaxy
  48. GRB 990510 Host Galaxy Discovery
  49. IPN localization of GRB000727
  50. GRB 990712: Late time HST/STIS Observations
  51. GRB 991216, HST/STIS observations
  52. GRB000620, Radio Observations
  53. GRB000630, optical observations
  54. GRB000630, Revised BVRI Field Photometry
  55. GRB000630, Optical Observations
  56. GRB000630, optical observations
  57. GRB000630, optical observations
  58. GRB000630, BVRI Field Photometry
  59. GRB000630, optical observations
  60. GRB000630: Optical observations
  61. GRB000630, Radio Observations
  62. possible optical counterpart of GRB 000630
  63. GRB 000620, optical observations
  64. GRB000418, HST/STIS Observations
  65. GRB990123: Late-time HST/STIS observations of the host
  66. GRB000620, optical observations
  67. GRB000615: H-band observations
  68. GRB990308, HST/STIS observations of the host galaxy
  69. GRB000620 - Optical observations
  70. GRB000620 Optical observations
  71. GRB000620: BeppoSAX WFC and GRBM detection
  72. GRB000607, optical observations
  73. GRB 000615: NIR further observations
  74. GRB990123, HST/STIS observations of the host galaxy
  75. GRB000616 optical observations
  76. GRB 000615, near-infrared observations
  77. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  78. GRB000615, further R-band photometry
  79. GRB 000615: NIR observations
  80. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  81. GRB000615, R-band photometry
  82. The Hosts of GRB 980703 and GRB 971214
  83. GRB 000301C: Further Late-Time HST/STIS observations
  84. GRB000528: follow-up X-ray measurements and update of IPN annulus
  85. GRB980519, HST/STIS observations of the host galaxy
  86. GRB000604 optical non-detection
  87. GRB000604 - Optical observations
  88. GRB000604, optical observations
  89. GRB000528, optical observations at ESO
  90. GRB 000604 optical observations
  91. GRB 000418: Detection of the Host Galaxy
  92. GRB000604, optical observations, comparison with DPOSS
  93. GRB000528, Radio Observations
  94. X-ray Afterglow of GRB 000529
  95. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  96. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  97. GRB 000528 - WFC measurements
  98. GRB000519, BVRI field photometry
  99. IPN triangulation of GRB000519
  100. GRB000508B, optical photometry

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