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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"

25980 results found.

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

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