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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"

38362 results found.

  1. GRB000926 - Optical observations
  2. GRB000926 - Optical observations
  3. GRB 000926, Optical Decay
  4. GRB000911: VLT infrared observation
  5. GRB000926 - Optical observations
  6. GRB 000926: optical observations
  7. GRB 000926, Optical Observations
  8. GRB000926 K'-band Observation
  9. GRB000926 : increasing optical decay slope
  10. GRB000926 optical observations
  11. J and K band observations of GRB 000926
  12. GRB 000926: Lightcurve Update and Predictions
  13. GRB 000926, optical observation by Oksanen (vsnet-grb)
  14. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  15. GRB000926: Optical observations
  16. CONCAM crude optical limits before and after GRB000926
  17. GRB 000926: Preliminary R-band Lightcurve
  18. GRB 000926 HST/Chandra TOO Status
  19. Spectroscopic Redshift of GRB 000926
  20. GRB 000926, Optical Observation
  21. GRB000926, radio observations
  22. GRB 000926: Optical candidate
  23. Optical candidate for GRB000926
  24. IPN triangulation of GRB000926
  25. GRB 000911, BVRI field photometry
  26. GRB000911: Sub-millimeter observations
  27. IPN triangulation of GRB000925
  28. GRB000911: Optical Transient
  29. GRB000911, Radio and Optical observations
  30. GRB000911, Radio observations
  31. GRB000911: Optical observations
  32. IPN triangulation of GRB000911
  33. IPN triangulation of GRB000910
  34. False GRB alarm from RXTE/ASM on 8 Sept 2000
  35. GRB 000830: Optical observations
  36. GRB000830: Optical observations
  37. GRB000830, TNG B-band observations
  38. GRB000830, BVRI field photometry
  39. GRB000830: Optical observations
  40. GRB000210, Optical observations
  41. "Snapshot" afterglow IDs and GRB 000830
  42. IPN triangulation of GRB000830
  43. HST/STIS observations of the host galaxy of GRB 980329
  44. HST/STIS observations of the chaotic environment of GRB 980613
  45. IPN localization of GRB000820
  46. SGR 1806-20 burst activity
  47. GRB000812, TNG R-band observations
  48. GRB000801 & GRB000730, Gamma Ray Observations
  49. GRB000730, Gamma Ray Observations
  50. GRB000812, Radio observations
  51. IPN localization of GRB000812
  52. IPN localization of GRB000811
  53. GRB000801, Gamma Ray Observations
  54. GRB000801, VLT-Antu R-band observations
  55. GRB000301C, UBVI optical observations
  56. GRB000801, Radio Observations
  57. GRB 991208 Host Galaxy Imaging
  58. Updated IPN coordinates for GRB000801
  59. IPN localization of GRB000801
  60. IPN localization of GRB000730B
  61. IPN localization of GRB000730B
  62. IPN localization of GRB000730
  63. GRB 990510: Possible detection of a host galaxy
  64. GRB 990510 Host Galaxy Discovery
  65. GRB 000727, optical observations
  66. IPN localization of GRB000727
  67. GRB 990705, HST/STIS observations of the host galaxy
  68. GRB 990712: Late time HST/STIS Observations
  69. GRB 991216, HST/STIS observations
  70. GRB000620, Radio Observations
  71. GRB981226, HST/STIS observations of the host galaxy
  72. GRB000630, optical observations
  73. GRB 000630: Detection of the Optical Afterglow
  74. GRB000630, Revised BVRI Field Photometry
  75. GRB000630, Optical Observations
  76. GRB000630, optical observations
  77. GRB000630, optical observations
  78. GRB000630, BVRI Field Photometry
  79. GRB000630, optical observations
  80. GRB000630, optical observations
  81. GRB000630: Optical observations
  82. GRB000630, Radio Observations
  83. possible optical counterpart of GRB 000630
  84. IPN triangulation of GRB000630
  85. GRB 000623, optical observations
  86. GRB 000620, optical observations
  87. GRB000418, HST/STIS Observations
  88. GRB990123: Late-time HST/STIS observations of the host
  89. GRB 990506, HST/STIS Observations of the Host Galaxy
  90. GRB000623
  91. GRB 000620: J-band observations
  92. GRB000620, optical observations
  93. GRB000615: H-band observations
  94. GRB990308, HST/STIS observations of the host galaxy
  95. GRB000620 Optical observations
  96. IPN annulus for GRB000620
  97. GRB000620: BeppoSAX WFC and GRBM detection
  98. GRB000615, Radio observations
  99. GRB000607, optical observations
  100. GRB 000615: NIR further observations

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