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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"

41685 results found.

  1. GRB 001109 X-ray afterglow with BeppoSAX
  2. CORRECTION to XMM-Newton observation of GRB001025
  3. GRB001109: Optical observations
  4. GRB001109: BeppoSAX/NFI Observations
  5. GRB001109, R-band optical observations
  6. GRB001109, Radio observations
  7. GRB001105 BVRI field photometry correction
  8. GRB001105, BVRI field photometry
  9. GRB 001105, R-band observation
  10. GRB 001025B, Optical obervations
  11. GRB 991208: HST Imaging of the Host Galaxy
  12. GRB000926: R-image of the host galaxy
  13. GRB 001025B, I-band observations
  14. XMM-Newton observation of GRB001025
  15. GRB001025B, Radio observations
  16. GRB 001025 Optical Observations
  17. GRB 001025A, optical observation
  18. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  19. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  20. IPN triangulation of GRB001025
  21. GRB001007: Optical observations
  22. ASM Localization of GRB 001025
  23. GRB001007, Radio observations
  24. GRB001019, Optical Observations
  25. GRB 001018, Possible Radio Afterglow
  26. GRB001018, Gamma Ray Observations
  27. CORRECTION TO PEAK FLUX OF GRB001018
  28. GRB 000926: Improved Absorber Redshift
  29. V,R,I band observations of GRB000926
  30. The Likely Optical/Infrared Afterglow of GRB 001011
  31. HETE positions added to GCN
  32. GRB001011 BeppoSAX/WFC refined position
  33. GRB 001007, BVR-band observations
  34. GRB000926 - Amateur Optical Observations
  35. GRB001007: Optical observations
  36. CONCAM null result on GRB001005
  37. GRB 000926 : the host galaxy
  38. HETE-2 Launches Successfully
  39. GRB 000926 Chandra Observation
  40. Public availability of BeppoSAX data of GRB000926
  41. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  42. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  43. GRB000926 - Optical observations
  44. GRB000926 - Optical observations
  45. GRB 000926, Optical Decay
  46. GRB000911: VLT infrared observation
  47. GRB000926 - Optical observations
  48. GRB000926 - Optical observations
  49. GRB 000926: optical observations
  50. GRB 000926, Optical Observations
  51. GRB000926 - Optical observations
  52. GRB000911: optical VLT observations
  53. GRB000926 K'-band Observation
  54. GRB000926 : increasing optical decay slope
  55. GRB000926 optical observations
  56. GRB000926 - Optical observations
  57. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  58. J and K band observations of GRB 000926
  59. GRB000911 Optical Observations
  60. GRB 000926: Lightcurve Update and Predictions
  61. GRB 000926, optical observation by Oksanen (vsnet-grb)
  62. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  63. GRB000926: Optical observations
  64. CONCAM crude optical limits before and after GRB000926
  65. GRB 000926: Preliminary R-band Lightcurve
  66. GRB 000926 HST/Chandra TOO Status
  67. Spectroscopic Redshift of GRB 000926
  68. GRB 000926, Optical Observation
  69. GRB000926, radio observations
  70. GRB 000926: Optical candidate
  71. Optical candidate for GRB000926
  72. IPN triangulation of GRB000926
  73. GRB 000911, BVRI field photometry
  74. GRB000911: Corrected coordinates
  75. GRB000911: Sub-millimeter observations
  76. GRB000911: Optical Transient
  77. GRB000911, Radio and Optical observations
  78. GRB000911, Radio observations
  79. GRB000911: Optical observations
  80. False GRB alarm from RXTE/ASM on 8 Sept 2000
  81. GRB 000830: Optical observations
  82. GRB000830: Optical observations
  83. GRB000830, TNG B-band observations
  84. GRB000830, BVRI field photometry
  85. GRB000830: Optical observations
  86. GRB000210, Optical observations
  87. Chandra Position of GRB000210
  88. "Snapshot" afterglow IDs and GRB 000830
  89. GRB000830: Optical observations
  90. HST/STIS observations of the host galaxy of GRB 980329
  91. HST/STIS observations of the chaotic environment of GRB 980613
  92. GRB000812, TNG R-band observations
  93. GRB000801 & GRB000730, Gamma Ray Observations
  94. GRB000730, Gamma Ray Observations
  95. GRB000812, Radio observations
  96. GRB000801, Gamma Ray Observations
  97. GRB000801, VLT-Antu R-band observations
  98. GRB000301C, UBVI optical observations
  99. GRB000801, Radio Observations
  100. GRB 991208 Host Galaxy Imaging

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