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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"

36804 results found.

  1. GRB001120: Optical observations
  2. GRB001109, optical observations
  3. GRB001120, optical observations
  4. IPN triangulation of GRB001120
  5. Optical/NIR observations of GRB001109
  6. GRB 001109: deep JHK upper limits
  7. GRB 001109 X-ray afterglow with BeppoSAX
  8. GRB001109: Optical observations
  9. GRB001109: BeppoSAX/NFI Observations
  10. GRB001109, R-band optical observations
  11. GRB001109, Radio observations
  12. BeppoSAX ALERT: GRB001109
  13. GRB001105 BVRI field photometry correction
  14. GRB001105, BVRI field photometry
  15. GRB 001105, R-band observation
  16. IPN TRIANGULATION OF GRB001105
  17. GRB 001025B, Optical obervations
  18. GRB 991208: HST Imaging of the Host Galaxy
  19. GRB000926: R-image of the host galaxy
  20. GRB 001025B, I-band observations
  21. GRB 001025 Optical Observations
  22. GRB 001025A, optical observation
  23. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  24. IPN triangulation of GRB001025
  25. ASM Localization of GRB 001025
  26. GRB001007, Radio observations
  27. IPN TRIANGULATION OF GRB001020
  28. GRB001019, Optical Observations
  29. GRB 001018, Possible Radio Afterglow
  30. GRB001018, Gamma Ray Observations
  31. IPN TRIANGULATION OF GRB001019
  32. IPN TRIANGULATION OF GRB001018
  33. IPN TRIANGULATION OF GRB 001017
  34. GRB 000926: Improved Absorber Redshift
  35. V,R,I band observations of GRB000926
  36. The Likely Optical/Infrared Afterglow of GRB 001011
  37. HETE positions added to GCN
  38. BeppoSAX ALERT: GRB001011
  39. GRB 001007, BVR-band observations
  40. GRB000926 - Amateur Optical Observations
  41. CONCAM null result on GRB001005
  42. IPN triangulation of GRB001007
  43. GRB 000926 : the host galaxy
  44. IPN triangulation of GRB001005
  45. GRB 000926 Chandra Observation
  46. IPN triangulation of GRB 001004
  47. Public availability of BeppoSAX data of GRB000926
  48. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  49. GRB 000926, Optical Decay
  50. GRB000926 - Optical observations
  51. GRB000926 - Optical observations
  52. GRB 000926: optical observations
  53. GRB 000926, Optical Observations
  54. GRB000926 K'-band Observation
  55. GRB000926 : increasing optical decay slope
  56. GRB000926 optical observations
  57. GRB000926 - Optical observations
  58. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  59. J and K band observations of GRB 000926
  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. CONCAM crude optical limits before and after GRB000926
  64. GRB 000926: Preliminary R-band Lightcurve
  65. GRB 000926 HST/Chandra TOO Status
  66. Spectroscopic Redshift of GRB 000926
  67. GRB 000926, Optical Observation
  68. GRB 000926: Optical candidate
  69. Optical candidate for GRB000926
  70. IPN triangulation of GRB000926
  71. GRB 000911, BVRI field photometry
  72. GRB000911: Sub-millimeter observations
  73. IPN triangulation of GRB000925
  74. IPN triangulation of GRB000911
  75. IPN triangulation of GRB000910
  76. False GRB alarm from RXTE/ASM on 8 Sept 2000
  77. GRB 000830: Optical observations
  78. GRB000830: Optical observations
  79. GRB000830, TNG B-band observations
  80. GRB000830, BVRI field photometry
  81. GRB000830: Optical observations
  82. GRB000210, Optical observations
  83. Chandra Position of GRB000210
  84. "Snapshot" afterglow IDs and GRB 000830
  85. IPN triangulation of GRB000830
  86. HST/STIS observations of the host galaxy of GRB 980329
  87. HST/STIS observations of the chaotic environment of GRB 980613
  88. IPN localization of GRB000820
  89. GRB000801 & GRB000730, Gamma Ray Observations
  90. GRB000730, Gamma Ray Observations
  91. GRB000812, Radio observations
  92. IPN localization of GRB000812
  93. IPN localization of GRB000811
  94. GRB000801, Gamma Ray Observations
  95. GRB000801, VLT-Antu R-band observations
  96. GRB 991208 Host Galaxy Imaging
  97. Updated IPN coordinates for GRB000801
  98. IPN localization of GRB000801
  99. IPN localization of GRB000730B
  100. IPN localization of GRB000730B

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