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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"

27393 results found.

  1. GRB010220: BeppoSAX WFC and GRBM preliminary data
  2. GRB010214, candidate optical afterglow
  3. GRB010214, optical observations
  4. GRB010214: BeppoSAX WFC and GRBM preliminary data
  5. GRB 010214: X-Ray afterglow
  6. GRB 010214 optical observation
  7. GRB010213, Radio Observations
  8. J-Band Observation of GRB 010214.
  9. GRB010213, Near-IR observations
  10. Possible InfraRed Transient of GRB 010214.
  11. GRB 010214, optical observations
  12. GRB010213 detected by HETE
  13. IPN Status Report
  14. HETE Status
  15. IPN/RXTE TRIANGULATION OF GRB010126
  16. GRB010126 Optical Observations
  17. IPN TRIANGULATION OF GRB010126
  18. Optical Observations of GRB 001018 at Keck
  19. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  20. Optical observations of GRB 001018 with JCAM
  21. IPN TRIANGULATION OF GRB010115
  22. IPN TRIANGULATION OF GRB010109
  23. IPN TRIANGULATION OF GRB010109
  24. IPN triangulation of GRB010104
  25. IPN triangulation of GRB010103
  26. H band observation of GRB 001212
  27. IPN triangulation of GRB001219
  28. GRB 001212 Optical Observation
  29. GRB 001212 Optical Observation
  30. GRB 001212 possible OA in 2MASS
  31. IPN triangulation of GRB001212
  32. Confirmation of IPN position for GRB001204
  33. IPN triangulation of GRB001204 (short/hard)
  34. GRB001120, optical observations
  35. WSRT 4.8 GHz observations of GRB001109
  36. IPN triangulation of GRB001120
  37. GRB 001109: deep JHK upper limits
  38. GRB 001109 X-ray afterglow with BeppoSAX
  39. CORRECTION to XMM-Newton observation of GRB001025
  40. GRB001109, Radio observations
  41. GRB001105 BVRI field photometry correction
  42. GRB001105, BVRI field photometry
  43. IPN TRIANGULATION OF GRB001105
  44. GRB 001025B, Optical obervations
  45. GRB 991208: HST Imaging of the Host Galaxy
  46. GRB 001025B, I-band observations
  47. XMM-Newton observation of GRB001025
  48. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  49. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  50. GRB001007: Optical observations
  51. ASM Localization of GRB 001025
  52. GRB001007, Radio observations
  53. GRB 001018, Possible Radio Afterglow
  54. GRB001018, Gamma Ray Observations
  55. IPN TRIANGULATION OF GRB001019
  56. IPN TRIANGULATION OF GRB001018
  57. IPN TRIANGULATION OF GRB 001017
  58. V,R,I band observations of GRB000926
  59. HETE positions added to GCN
  60. GRB000926 - Amateur Optical Observations
  61. CONCAM null result on GRB001005
  62. IPN triangulation of GRB001005
  63. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  64. GRB000926 - Optical observations
  65. GRB000926 - Optical observations
  66. GRB 000926, Optical Decay
  67. GRB000911: VLT infrared observation
  68. GRB 000926, Optical Observations
  69. GRB000926 K'-band Observation
  70. J and K band observations of GRB 000926
  71. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  72. CONCAM crude optical limits before and after GRB000926
  73. GRB 000926: Preliminary R-band Lightcurve
  74. Spectroscopic Redshift of GRB 000926
  75. GRB 000926: Optical candidate
  76. Optical candidate for GRB000926
  77. GRB 000911, BVRI field photometry
  78. GRB000911, Radio and Optical observations
  79. GRB000911: Optical observations
  80. GRB000830, BVRI field photometry
  81. GRB000210, Optical observations
  82. "Snapshot" afterglow IDs and GRB 000830
  83. GRB000730, Gamma Ray Observations
  84. GRB000812, Radio observations
  85. GRB000801, Gamma Ray Observations
  86. GRB000801, VLT-Antu R-band observations
  87. GRB 991208 Host Galaxy Imaging
  88. IPN localization of GRB000730B
  89. GRB 990510: Possible detection of a host galaxy
  90. GRB 990510 Host Galaxy Discovery
  91. IPN localization of GRB000727
  92. GRB 990712: Late time HST/STIS Observations
  93. GRB 991216, HST/STIS observations
  94. GRB000620, Radio Observations
  95. GRB000630, optical observations
  96. GRB000630, Revised BVRI Field Photometry
  97. GRB000630, Optical Observations
  98. GRB000630, optical observations
  99. GRB000630, optical observations
  100. GRB000630, BVRI Field Photometry

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