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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"

24978 results found.

  1. GRB010126 Optical Observations
  2. IPN TRIANGULATION OF GRB010126
  3. Optical Observations of GRB 001018 at Keck
  4. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  5. Optical observations of GRB 001018 with JCAM
  6. IPN TRIANGULATION OF GRB010115
  7. IPN TRIANGULATION OF GRB010109
  8. IPN TRIANGULATION OF GRB010109
  9. IPN triangulation of GRB010104
  10. IPN triangulation of GRB010103
  11. H band observation of GRB 001212
  12. IPN triangulation of GRB001219
  13. GRB 001212 Optical Observation
  14. GRB 001212 Optical Observation
  15. GRB 001212 possible OA in 2MASS
  16. IPN triangulation of GRB001212
  17. Confirmation of IPN position for GRB001204
  18. IPN triangulation of GRB001204 (short/hard)
  19. GRB001120, optical observations
  20. WSRT 4.8 GHz observations of GRB001109
  21. IPN triangulation of GRB001120
  22. GRB 001109: deep JHK upper limits
  23. GRB 001109 X-ray afterglow with BeppoSAX
  24. CORRECTION to XMM-Newton observation of GRB001025
  25. GRB001109, Radio observations
  26. GRB001105 BVRI field photometry correction
  27. GRB001105, BVRI field photometry
  28. IPN TRIANGULATION OF GRB001105
  29. GRB 001025B, Optical obervations
  30. GRB 991208: HST Imaging of the Host Galaxy
  31. GRB 001025B, I-band observations
  32. XMM-Newton observation of GRB001025
  33. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  34. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  35. GRB001007: Optical observations
  36. ASM Localization of GRB 001025
  37. GRB001007, Radio observations
  38. GRB 001018, Possible Radio Afterglow
  39. GRB001018, Gamma Ray Observations
  40. IPN TRIANGULATION OF GRB001019
  41. IPN TRIANGULATION OF GRB001018
  42. IPN TRIANGULATION OF GRB 001017
  43. V,R,I band observations of GRB000926
  44. HETE positions added to GCN
  45. GRB000926 - Amateur Optical Observations
  46. CONCAM null result on GRB001005
  47. IPN triangulation of GRB001005
  48. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  49. GRB000926 - Optical observations
  50. GRB000926 - Optical observations
  51. GRB 000926, Optical Decay
  52. GRB000911: VLT infrared observation
  53. GRB 000926, Optical Observations
  54. GRB000926 K'-band Observation
  55. J and K band observations of GRB 000926
  56. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  57. CONCAM crude optical limits before and after GRB000926
  58. GRB 000926: Preliminary R-band Lightcurve
  59. Spectroscopic Redshift of GRB 000926
  60. GRB 000926: Optical candidate
  61. Optical candidate for GRB000926
  62. GRB 000911, BVRI field photometry
  63. GRB000911, Radio and Optical observations
  64. GRB000911: Optical observations
  65. GRB000830, BVRI field photometry
  66. GRB000210, Optical observations
  67. "Snapshot" afterglow IDs and GRB 000830
  68. GRB000730, Gamma Ray Observations
  69. GRB000812, Radio observations
  70. GRB000801, Gamma Ray Observations
  71. GRB000801, VLT-Antu R-band observations
  72. GRB 991208 Host Galaxy Imaging
  73. IPN localization of GRB000730B
  74. GRB 990510: Possible detection of a host galaxy
  75. GRB 990510 Host Galaxy Discovery
  76. IPN localization of GRB000727
  77. GRB 990712: Late time HST/STIS Observations
  78. GRB 991216, HST/STIS observations
  79. GRB000620, Radio Observations
  80. GRB000630, optical observations
  81. GRB000630, Revised BVRI Field Photometry
  82. GRB000630, Optical Observations
  83. GRB000630, optical observations
  84. GRB000630, optical observations
  85. GRB000630, BVRI Field Photometry
  86. GRB000630, optical observations
  87. GRB000630: Optical observations
  88. GRB000630, Radio Observations
  89. possible optical counterpart of GRB 000630
  90. GRB 000620, optical observations
  91. GRB000418, HST/STIS Observations
  92. GRB990123: Late-time HST/STIS observations of the host
  93. GRB000620, optical observations
  94. GRB000615: H-band observations
  95. GRB990308, HST/STIS observations of the host galaxy
  96. GRB000620 - Optical observations
  97. GRB000620 Optical observations
  98. GRB000620: BeppoSAX WFC and GRBM detection
  99. GRB000607, optical observations
  100. GRB 000615: NIR further observations

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