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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"

25716 results found.

  1. GRB010222 - Optical observation
  2. GRB 010222: High-Resolution Keck Spectroscopy
  3. GRB 010214, I-band data
  4. GRB 010222
  5. GRB010222 further R-band photometry
  6. GRB010222: R-band data
  7. GRB 010222: Keck Spectroscopy
  8. GRB010214, field photometry
  9. GRB010222, field photometry
  10. GRB010222 further R-band photometry
  11. GRB010222, possible increase of optical decay slope
  12. GRB 010222 Kyoto optical observation
  13. GRB010222 R-BAND OBSERVATION
  14. GRB010214 follow-up from Hanle
  15. GRB 010222: Near-IR Observations
  16. GRB 010222: Optical Observations
  17. GRB010222: Optical decay slope
  18. GRB 010214, Optical Observations
  19. GRB010222, radio observations
  20. GRB010222, optical observations
  21. GRB010222: BeppoSAX/NFI Observations
  22. GRB010214B,Gamma Ray Observations
  23. GRB 010220, simultaneous optical observations
  24. GRB010220: BeppoSAX WFC and GRBM preliminary data
  25. GRB010214, candidate optical afterglow
  26. GRB010214, optical observations
  27. GRB010214: BeppoSAX WFC and GRBM preliminary data
  28. GRB 010214: X-Ray afterglow
  29. GRB 010214 optical observation
  30. GRB010213, Radio Observations
  31. J-Band Observation of GRB 010214.
  32. GRB010213, Near-IR observations
  33. Possible InfraRed Transient of GRB 010214.
  34. GRB 010214, optical observations
  35. GRB010213 detected by HETE
  36. IPN Status Report
  37. HETE Status
  38. IPN/RXTE TRIANGULATION OF GRB010126
  39. GRB010126 Optical Observations
  40. IPN TRIANGULATION OF GRB010126
  41. Optical Observations of GRB 001018 at Keck
  42. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  43. Optical observations of GRB 001018 with JCAM
  44. IPN TRIANGULATION OF GRB010115
  45. IPN TRIANGULATION OF GRB010109
  46. IPN TRIANGULATION OF GRB010109
  47. IPN triangulation of GRB010104
  48. IPN triangulation of GRB010103
  49. H band observation of GRB 001212
  50. IPN triangulation of GRB001219
  51. GRB 001212 Optical Observation
  52. GRB 001212 Optical Observation
  53. GRB 001212 possible OA in 2MASS
  54. IPN triangulation of GRB001212
  55. Confirmation of IPN position for GRB001204
  56. IPN triangulation of GRB001204 (short/hard)
  57. GRB001120, optical observations
  58. WSRT 4.8 GHz observations of GRB001109
  59. IPN triangulation of GRB001120
  60. GRB 001109: deep JHK upper limits
  61. GRB 001109 X-ray afterglow with BeppoSAX
  62. CORRECTION to XMM-Newton observation of GRB001025
  63. GRB001109, Radio observations
  64. GRB001105 BVRI field photometry correction
  65. GRB001105, BVRI field photometry
  66. IPN TRIANGULATION OF GRB001105
  67. GRB 001025B, Optical obervations
  68. GRB 991208: HST Imaging of the Host Galaxy
  69. GRB 001025B, I-band observations
  70. XMM-Newton observation of GRB001025
  71. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  72. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  73. GRB001007: Optical observations
  74. ASM Localization of GRB 001025
  75. GRB001007, Radio observations
  76. GRB 001018, Possible Radio Afterglow
  77. GRB001018, Gamma Ray Observations
  78. IPN TRIANGULATION OF GRB001019
  79. IPN TRIANGULATION OF GRB001018
  80. IPN TRIANGULATION OF GRB 001017
  81. V,R,I band observations of GRB000926
  82. HETE positions added to GCN
  83. GRB000926 - Amateur Optical Observations
  84. CONCAM null result on GRB001005
  85. IPN triangulation of GRB001005
  86. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  87. GRB000926 - Optical observations
  88. GRB000926 - Optical observations
  89. GRB 000926, Optical Decay
  90. GRB000911: VLT infrared observation
  91. GRB 000926, Optical Observations
  92. GRB000926 K'-band Observation
  93. J and K band observations of GRB 000926
  94. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  95. CONCAM crude optical limits before and after GRB000926
  96. GRB 000926: Preliminary R-band Lightcurve
  97. Spectroscopic Redshift of GRB 000926
  98. GRB 000926: Optical candidate
  99. Optical candidate for GRB000926
  100. GRB 000911, BVRI field photometry

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