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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"

38394 results found.

  1. GRB 001025A, optical observation
  2. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  3. IPN triangulation of GRB001025
  4. GRB001007: Optical observations
  5. ASM Localization of GRB 001025
  6. GRB001007, Radio observations
  7. IPN TRIANGULATION OF GRB001020
  8. GRB001019, Optical Observations
  9. GRB 001018, Possible Radio Afterglow
  10. GRB001018, Gamma Ray Observations
  11. IPN TRIANGULATION OF GRB001019
  12. IPN TRIANGULATION OF GRB001018
  13. IPN TRIANGULATION OF GRB 001017
  14. GRB 000926: Improved Absorber Redshift
  15. V,R,I band observations of GRB000926
  16. The Likely Optical/Infrared Afterglow of GRB 001011
  17. HETE positions added to GCN
  18. GRB001011 BeppoSAX/WFC refined position
  19. BeppoSAX ALERT: GRB001011
  20. GRB 001007, BVR-band observations
  21. GRB000926 - Amateur Optical Observations
  22. GRB001007: Optical observations
  23. CONCAM null result on GRB001005
  24. IPN triangulation of GRB001007
  25. GRB 000926 : the host galaxy
  26. HETE-2 Launches Successfully
  27. IPN triangulation of GRB001005
  28. HETE-2 48 hour Launch Delay
  29. GRB 000926 Chandra Observation
  30. IPN triangulation of GRB 001004
  31. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  32. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  33. GRB000926 - Optical observations
  34. GRB000926 - Optical observations
  35. GRB 000926, Optical Decay
  36. GRB000911: VLT infrared observation
  37. GRB000926 - Optical observations
  38. GRB 000926: optical observations
  39. GRB 000926, Optical Observations
  40. GRB000926 K'-band Observation
  41. GRB000926 : increasing optical decay slope
  42. GRB000926 optical observations
  43. J and K band observations of GRB 000926
  44. GRB 000926: Lightcurve Update and Predictions
  45. GRB 000926, optical observation by Oksanen (vsnet-grb)
  46. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  47. GRB000926: Optical observations
  48. CONCAM crude optical limits before and after GRB000926
  49. GRB 000926: Preliminary R-band Lightcurve
  50. GRB 000926 HST/Chandra TOO Status
  51. Spectroscopic Redshift of GRB 000926
  52. GRB 000926, Optical Observation
  53. GRB000926, radio observations
  54. GRB 000926: Optical candidate
  55. Optical candidate for GRB000926
  56. IPN triangulation of GRB000926
  57. GRB 000911, BVRI field photometry
  58. GRB000911: Sub-millimeter observations
  59. IPN triangulation of GRB000925
  60. GRB000911: Optical Transient
  61. GRB000911, Radio and Optical observations
  62. GRB000911, Radio observations
  63. GRB000911: Optical observations
  64. IPN triangulation of GRB000911
  65. IPN triangulation of GRB000910
  66. False GRB alarm from RXTE/ASM on 8 Sept 2000
  67. GRB 000830: Optical observations
  68. GRB000830: Optical observations
  69. GRB000830, TNG B-band observations
  70. GRB000830, BVRI field photometry
  71. GRB000830: Optical observations
  72. GRB000210, Optical observations
  73. "Snapshot" afterglow IDs and GRB 000830
  74. IPN triangulation of GRB000830
  75. HST/STIS observations of the host galaxy of GRB 980329
  76. HST/STIS observations of the chaotic environment of GRB 980613
  77. IPN localization of GRB000820
  78. SGR 1806-20 burst activity
  79. GRB000812, TNG R-band observations
  80. GRB000801 & GRB000730, Gamma Ray Observations
  81. GRB000730, Gamma Ray Observations
  82. GRB000812, Radio observations
  83. IPN localization of GRB000812
  84. IPN localization of GRB000811
  85. GRB000801, Gamma Ray Observations
  86. GRB000801, VLT-Antu R-band observations
  87. GRB000301C, UBVI optical observations
  88. GRB000801, Radio Observations
  89. GRB 991208 Host Galaxy Imaging
  90. Updated IPN coordinates for GRB000801
  91. IPN localization of GRB000801
  92. IPN localization of GRB000730B
  93. IPN localization of GRB000730B
  94. IPN localization of GRB000730
  95. GRB 990510: Possible detection of a host galaxy
  96. GRB 990510 Host Galaxy Discovery
  97. GRB 000727, optical observations
  98. IPN localization of GRB000727
  99. GRB 990705, HST/STIS observations of the host galaxy
  100. GRB 990712: Late time HST/STIS Observations

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