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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"

45499 results found.

  1. IPN triangulation of GRB010103
  2. GRB 001204: Ks observations
  3. H band observation of GRB 001212
  4. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  5. IPN triangulation of GRB001219
  6. GRB 001212 Optical Observation
  7. GRB 001212 Optical Observation
  8. GRB 001212 optical observation
  9. GRB 001212 possible OA in 2MASS
  10. GRB 001212 possible OA
  11. IPN triangulation of GRB001212
  12. GRB001204: Optical observations
  13. Confirmation of IPN position for GRB001204
  14. GRB001204, Radio observations
  15. IPN triangulation of GRB001204 (short/hard)
  16. GRB 001105, further optical observations
  17. GRB001120: Gunn-i observations
  18. GRB001120: Optical observations
  19. GRB001109, optical observations
  20. GRB001120, optical observations
  21. WSRT 4.8 GHz observations of GRB001109
  22. IPN triangulation of GRB001120
  23. Optical/NIR observations of GRB001109
  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: Optical observations
  28. GRB001109: BeppoSAX/NFI Observations
  29. GRB001109, R-band optical observations
  30. GRB001109, Radio observations
  31. GRB001109: BeppoSAX refined WFC position
  32. BeppoSAX ALERT: GRB001109
  33. GRB001105, BVRI field photometry
  34. GRB 001105, R-band observation
  35. IPN TRIANGULATION OF GRB001105
  36. GRB 001025B, Optical obervations
  37. GRB 991208: HST Imaging of the Host Galaxy
  38. GRB000926: R-image of the host galaxy
  39. GRB 001025B, I-band observations
  40. XMM-Newton observation of GRB001025
  41. GRB001025B, Radio observations
  42. GRB 001025 Optical Observations
  43. GRB 001025A, optical observation
  44. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  45. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  46. IPN triangulation of GRB001025
  47. GRB001007: Optical observations
  48. ASM Localization of GRB 001025
  49. GRB001007, Radio observations
  50. IPN TRIANGULATION OF GRB001020
  51. GRB001019, Optical Observations
  52. GRB 001018, Possible Radio Afterglow
  53. GRB001018, Gamma Ray Observations
  54. IPN TRIANGULATION OF GRB001019
  55. CORRECTION TO PEAK FLUX OF GRB001018
  56. IPN TRIANGULATION OF GRB001018
  57. IPN TRIANGULATION OF GRB 001017
  58. GRB 000926: Improved Absorber Redshift
  59. V,R,I band observations of GRB000926
  60. The Likely Optical/Infrared Afterglow of GRB 001011
  61. HETE positions added to GCN
  62. GRB001011 BeppoSAX/WFC refined position
  63. BeppoSAX ALERT: GRB001011
  64. GRB 001007, BVR-band observations
  65. GRB000926 - Amateur Optical Observations
  66. GRB001007: Optical observations
  67. CONCAM null result on GRB001005
  68. IPN triangulation of GRB001007
  69. GRB 000926 : the host galaxy
  70. HETE-2 Launches Successfully
  71. IPN triangulation of GRB001005
  72. HETE-2 48 hour Launch Delay
  73. GRB 000926 Chandra Observation
  74. IPN triangulation of GRB 001004
  75. Public availability of BeppoSAX data of GRB000926
  76. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  77. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  78. GRB000926 - Optical observations
  79. GRB000926 - Optical observations
  80. GRB 000926, Optical Decay
  81. GRB000911: VLT infrared observation
  82. GRB000926 - Optical observations
  83. GRB000926 - Optical observations
  84. GRB 000926: optical observations
  85. GRB 000926, Optical Observations
  86. GRB000926 - Optical observations
  87. GRB000911: optical VLT observations
  88. GRB000926 K'-band Observation
  89. GRB000926 : increasing optical decay slope
  90. GRB000926 optical observations
  91. GRB000926 - Optical observations
  92. J and K band observations of GRB 000926
  93. GRB000911 Optical Observations
  94. GRB 000926: Lightcurve Update and Predictions
  95. GRB 000926, optical observation by Oksanen (vsnet-grb)
  96. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  97. GRB000926: Optical observations
  98. CONCAM crude optical limits before and after GRB000926
  99. GRB 000926: Preliminary R-band Lightcurve
  100. GRB 000926 HST/Chandra TOO Status

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