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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"

24846 results found.

  1. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  2. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  3. GRB001007: Optical observations
  4. ASM Localization of GRB 001025
  5. GRB001007, Radio observations
  6. GRB 001018, Possible Radio Afterglow
  7. GRB001018, Gamma Ray Observations
  8. IPN TRIANGULATION OF GRB001019
  9. IPN TRIANGULATION OF GRB001018
  10. IPN TRIANGULATION OF GRB 001017
  11. V,R,I band observations of GRB000926
  12. HETE positions added to GCN
  13. GRB000926 - Amateur Optical Observations
  14. CONCAM null result on GRB001005
  15. IPN triangulation of GRB001005
  16. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  17. GRB000926 - Optical observations
  18. GRB000926 - Optical observations
  19. GRB 000926, Optical Decay
  20. GRB000911: VLT infrared observation
  21. GRB 000926, Optical Observations
  22. GRB000926 K'-band Observation
  23. J and K band observations of GRB 000926
  24. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  25. CONCAM crude optical limits before and after GRB000926
  26. GRB 000926: Preliminary R-band Lightcurve
  27. Spectroscopic Redshift of GRB 000926
  28. GRB 000926: Optical candidate
  29. Optical candidate for GRB000926
  30. GRB 000911, BVRI field photometry
  31. GRB000911, Radio and Optical observations
  32. GRB000911: Optical observations
  33. GRB000830, BVRI field photometry
  34. GRB000210, Optical observations
  35. "Snapshot" afterglow IDs and GRB 000830
  36. GRB000730, Gamma Ray Observations
  37. GRB000812, Radio observations
  38. GRB000801, Gamma Ray Observations
  39. GRB000801, VLT-Antu R-band observations
  40. GRB 991208 Host Galaxy Imaging
  41. IPN localization of GRB000730B
  42. GRB 990510: Possible detection of a host galaxy
  43. GRB 990510 Host Galaxy Discovery
  44. IPN localization of GRB000727
  45. GRB 990712: Late time HST/STIS Observations
  46. GRB 991216, HST/STIS observations
  47. GRB000620, Radio Observations
  48. GRB000630, optical observations
  49. GRB000630, Revised BVRI Field Photometry
  50. GRB000630, Optical Observations
  51. GRB000630, optical observations
  52. GRB000630, optical observations
  53. GRB000630, BVRI Field Photometry
  54. GRB000630, optical observations
  55. GRB000630: Optical observations
  56. GRB000630, Radio Observations
  57. possible optical counterpart of GRB 000630
  58. GRB 000620, optical observations
  59. GRB000418, HST/STIS Observations
  60. GRB990123: Late-time HST/STIS observations of the host
  61. GRB000620, optical observations
  62. GRB000615: H-band observations
  63. GRB990308, HST/STIS observations of the host galaxy
  64. GRB000620 - Optical observations
  65. GRB000620 Optical observations
  66. GRB000620: BeppoSAX WFC and GRBM detection
  67. GRB000607, optical observations
  68. GRB 000615: NIR further observations
  69. GRB990123, HST/STIS observations of the host galaxy
  70. GRB000616 optical observations
  71. GRB 000615, near-infrared observations
  72. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  73. GRB000615, further R-band photometry
  74. GRB 000615: NIR observations
  75. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  76. GRB000615, R-band photometry
  77. The Hosts of GRB 980703 and GRB 971214
  78. GRB 000301C: Further Late-Time HST/STIS observations
  79. GRB000528: follow-up X-ray measurements and update of IPN annulus
  80. GRB980519, HST/STIS observations of the host galaxy
  81. GRB000604 optical non-detection
  82. GRB000604 - Optical observations
  83. GRB000604, optical observations
  84. GRB000528, optical observations at ESO
  85. GRB 000604 optical observations
  86. GRB 000418: Detection of the Host Galaxy
  87. GRB000604, optical observations, comparison with DPOSS
  88. GRB000528, Radio Observations
  89. X-ray Afterglow of GRB 000529
  90. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  91. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  92. GRB 000528 - WFC measurements
  93. GRB000519, BVRI field photometry
  94. IPN triangulation of GRB000519
  95. GRB000508B, optical photometry
  96. GRB000508B, BVR field photometry
  97. Possible GRB-related phenomenon
  98. RXTE/ASM and IPN localization of GRB 000508B
  99. GRB000424, UBVRI field photometry
  100. GRB000418, UBVRI field photometry update

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