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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"

44383 results found.

  1. IPN triangulation of GRB001204 (short/hard)
  2. GRB 001105, further optical observations
  3. GRB001120: Gunn-i observations
  4. GRB001120: Optical observations
  5. GRB001109, optical observations
  6. GRB001120, optical observations
  7. WSRT 4.8 GHz observations of GRB001109
  8. IPN triangulation of GRB001120
  9. Optical/NIR observations of GRB001109
  10. GRB 001109: deep JHK upper limits
  11. GRB 001109 X-ray afterglow with BeppoSAX
  12. CORRECTION to XMM-Newton observation of GRB001025
  13. GRB001109: Optical observations
  14. GRB001109: BeppoSAX/NFI Observations
  15. GRB001109, R-band optical observations
  16. GRB001109, Radio observations
  17. GRB001109: BeppoSAX refined WFC position
  18. BeppoSAX ALERT: GRB001109
  19. GRB001105, BVRI field photometry
  20. GRB 001105, R-band observation
  21. IPN TRIANGULATION OF GRB001105
  22. GRB 001025B, Optical obervations
  23. GRB 991208: HST Imaging of the Host Galaxy
  24. GRB000926: R-image of the host galaxy
  25. GRB 001025B, I-band observations
  26. XMM-Newton observation of GRB001025
  27. GRB001025B, Radio observations
  28. GRB 001025 Optical Observations
  29. GRB 001025A, optical observation
  30. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  31. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  32. IPN triangulation of GRB001025
  33. GRB001007: Optical observations
  34. ASM Localization of GRB 001025
  35. GRB001007, Radio observations
  36. IPN TRIANGULATION OF GRB001020
  37. GRB001019, Optical Observations
  38. GRB 001018, Possible Radio Afterglow
  39. GRB001018, Gamma Ray Observations
  40. IPN TRIANGULATION OF GRB001019
  41. CORRECTION TO PEAK FLUX OF GRB001018
  42. IPN TRIANGULATION OF GRB001018
  43. IPN TRIANGULATION OF GRB 001017
  44. GRB 000926: Improved Absorber Redshift
  45. V,R,I band observations of GRB000926
  46. The Likely Optical/Infrared Afterglow of GRB 001011
  47. HETE positions added to GCN
  48. GRB001011 BeppoSAX/WFC refined position
  49. BeppoSAX ALERT: GRB001011
  50. GRB 001007, BVR-band observations
  51. GRB000926 - Amateur Optical Observations
  52. GRB001007: Optical observations
  53. CONCAM null result on GRB001005
  54. IPN triangulation of GRB001007
  55. GRB 000926 : the host galaxy
  56. HETE-2 Launches Successfully
  57. IPN triangulation of GRB001005
  58. HETE-2 48 hour Launch Delay
  59. GRB 000926 Chandra Observation
  60. IPN triangulation of GRB 001004
  61. Public availability of BeppoSAX data of GRB000926
  62. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  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. GRB000926 - Optical observations
  69. GRB000926 - Optical observations
  70. GRB 000926: optical observations
  71. GRB 000926, Optical Observations
  72. GRB000926 - Optical observations
  73. GRB000911: optical VLT observations
  74. GRB000926 K'-band Observation
  75. GRB000926 : increasing optical decay slope
  76. GRB000926 optical observations
  77. GRB000926 - Optical observations
  78. J and K band observations of GRB 000926
  79. GRB000911 Optical Observations
  80. GRB 000926: Lightcurve Update and Predictions
  81. GRB 000926, optical observation by Oksanen (vsnet-grb)
  82. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  83. GRB000926: Optical observations
  84. CONCAM crude optical limits before and after GRB000926
  85. GRB 000926: Preliminary R-band Lightcurve
  86. GRB 000926 HST/Chandra TOO Status
  87. Spectroscopic Redshift of GRB 000926
  88. GRB 000926, Optical Observation
  89. GRB000926, radio observations
  90. GRB 000926: Optical candidate
  91. Optical candidate for GRB000926
  92. IPN triangulation of GRB000926
  93. IPN triangulation of GRB000926
  94. GRB 000911, BVRI field photometry
  95. GRB000911: Corrected coordinates
  96. GRB000911: Sub-millimeter observations
  97. IPN triangulation of GRB000925
  98. GRB000911: Optical Transient
  99. GRB000911, Radio and Optical observations
  100. GRB000911, Radio observations

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