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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"

37931 results found.

  1. GRB010126, TNG R-band observations
  2. IPN TRIANGULATION OF GRB010126
  3. IPN/RXTE TRIANGULATION OF GRB010126
  4. GRB 010119, optical observations
  5. GRB010119: Optical observations
  6. Optical Observations of GRB 001018 at Keck
  7. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  8. Optical observations of GRB 001018 with JCAM
  9. IPN TRIANGULATION OF GRB010115
  10. IPN TRIANGULATION OF GRB010109
  11. GRB010103, optical observations
  12. IPN triangulation of GRB010104
  13. IPN triangulation of GRB010103
  14. GRB 001204: Ks observations
  15. H band observation of GRB 001212
  16. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  17. IPN triangulation of GRB001219
  18. GRB 001212 Optical Observation
  19. GRB 001212 Optical Observation
  20. GRB 001212 optical observation
  21. GRB 001212 possible OA in 2MASS
  22. GRB 001212 possible OA
  23. IPN triangulation of GRB001212
  24. Confirmation of IPN position for GRB001204
  25. IPN triangulation of GRB001204 (short/hard)
  26. GRB 001105, further optical observations
  27. GRB001120: Gunn-i observations
  28. GRB001120: Optical observations
  29. GRB001109, optical observations
  30. GRB001120, optical observations
  31. IPN triangulation of GRB001120
  32. Optical/NIR observations of GRB001109
  33. GRB 001109: deep JHK upper limits
  34. GRB 001109 X-ray afterglow with BeppoSAX
  35. GRB001109: Optical observations
  36. GRB001109: BeppoSAX/NFI Observations
  37. GRB001109, R-band optical observations
  38. GRB001109, Radio observations
  39. BeppoSAX ALERT: GRB001109
  40. GRB001105 BVRI field photometry correction
  41. GRB001105, BVRI field photometry
  42. GRB 001105, R-band observation
  43. IPN TRIANGULATION OF GRB001105
  44. GRB 001025B, Optical obervations
  45. GRB 991208: HST Imaging of the Host Galaxy
  46. GRB000926: R-image of the host galaxy
  47. GRB 001025B, I-band observations
  48. GRB 001025 Optical Observations
  49. GRB 001025A, optical observation
  50. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  51. IPN triangulation of GRB001025
  52. ASM Localization of GRB 001025
  53. GRB001007, Radio observations
  54. IPN TRIANGULATION OF GRB001020
  55. GRB001019, Optical Observations
  56. GRB 001018, Possible Radio Afterglow
  57. GRB001018, Gamma Ray Observations
  58. IPN TRIANGULATION OF GRB001019
  59. IPN TRIANGULATION OF GRB001018
  60. IPN TRIANGULATION OF GRB 001017
  61. GRB 000926: Improved Absorber Redshift
  62. V,R,I band observations of GRB000926
  63. The Likely Optical/Infrared Afterglow of GRB 001011
  64. HETE positions added to GCN
  65. BeppoSAX ALERT: GRB001011
  66. GRB 001007, BVR-band observations
  67. GRB000926 - Amateur Optical Observations
  68. CONCAM null result on GRB001005
  69. IPN triangulation of GRB001007
  70. GRB 000926 : the host galaxy
  71. IPN triangulation of GRB001005
  72. GRB 000926 Chandra Observation
  73. IPN triangulation of GRB 001004
  74. Public availability of BeppoSAX data of GRB000926
  75. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  76. GRB 000926, Optical Decay
  77. GRB000926 - Optical observations
  78. GRB000926 - Optical observations
  79. GRB 000926: optical observations
  80. GRB 000926, Optical Observations
  81. GRB000926 K'-band Observation
  82. GRB000926 : increasing optical decay slope
  83. GRB000926 optical observations
  84. GRB000926 - Optical observations
  85. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  86. J and K band observations of GRB 000926
  87. GRB 000926: Lightcurve Update and Predictions
  88. GRB 000926, optical observation by Oksanen (vsnet-grb)
  89. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  90. CONCAM crude optical limits before and after GRB000926
  91. GRB 000926: Preliminary R-band Lightcurve
  92. GRB 000926 HST/Chandra TOO Status
  93. Spectroscopic Redshift of GRB 000926
  94. GRB 000926, Optical Observation
  95. GRB 000926: Optical candidate
  96. Optical candidate for GRB000926
  97. IPN triangulation of GRB000926
  98. GRB 000911, BVRI field photometry
  99. GRB000911: Sub-millimeter observations
  100. IPN triangulation of GRB000925

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