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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"

27392 results found.

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

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