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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"

41622 results found.

  1. GRB 001007, BVR-band observations
  2. GRB000926 - Amateur Optical Observations
  3. GRB001007: Optical observations
  4. GRB 000926 : the host galaxy
  5. HETE-2 Launches Successfully
  6. GRB 000926 Chandra Observation
  7. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  8. GRB000926 - Optical observations
  9. GRB000926 - Optical observations
  10. GRB 000926, Optical Decay
  11. GRB000926 - Optical observations
  12. GRB000926 - Optical observations
  13. GRB 000926: optical observations
  14. GRB 000926, Optical Observations
  15. GRB000926 - Optical observations
  16. GRB000911: optical VLT observations
  17. GRB000926 K'-band Observation
  18. GRB000926 optical observations
  19. GRB000926 - Optical observations
  20. J and K band observations of GRB 000926
  21. GRB000911 Optical Observations
  22. GRB 000926: Lightcurve Update and Predictions
  23. GRB 000926, optical observation by Oksanen (vsnet-grb)
  24. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  25. GRB000926: Optical observations
  26. GRB 000926 HST/Chandra TOO Status
  27. Spectroscopic Redshift of GRB 000926
  28. GRB000926, radio observations
  29. GRB 000926: Optical candidate
  30. Optical candidate for GRB000926
  31. GRB 000911, BVRI field photometry
  32. GRB000911: Corrected coordinates
  33. GRB000911: Sub-millimeter observations
  34. GRB000911: Optical Transient
  35. GRB000911, Radio and Optical observations
  36. GRB000911, Radio observations
  37. GRB000911: Optical observations
  38. False GRB alarm from RXTE/ASM on 8 Sept 2000
  39. GRB 000830: Optical observations
  40. GRB000830: Optical observations
  41. GRB000830, TNG B-band observations
  42. GRB000830, BVRI field photometry
  43. GRB000830: Optical observations
  44. GRB000210, Optical observations
  45. Chandra Position of GRB000210
  46. "Snapshot" afterglow IDs and GRB 000830
  47. GRB000830: Optical observations
  48. IPN triangulation of GRB000830
  49. HST/STIS observations of the host galaxy of GRB 980329
  50. HST/STIS observations of the chaotic environment of GRB 980613
  51. SGR 1806-20 burst activity
  52. GRB000812, TNG R-band observations
  53. GRB000801 & GRB000730, Gamma Ray Observations
  54. GRB000730, Gamma Ray Observations
  55. GRB000812, Radio observations
  56. GRB000801, Gamma Ray Observations
  57. GRB000801, VLT-Antu R-band observations
  58. GRB000301C, UBVI optical observations
  59. GRB000801, Radio Observations
  60. GRB 991208 Host Galaxy Imaging
  61. GRB 990510: Possible detection of a host galaxy
  62. GRB 990510 Host Galaxy Discovery
  63. GRB 000727, optical observations
  64. GRB 990705, HST/STIS observations of the host galaxy
  65. GRB 990712: Late time HST/STIS Observations
  66. GRB 991216, HST/STIS observations
  67. GRB000620, Radio Observations
  68. GRB981226, HST/STIS observations of the host galaxy
  69. GRB000630, optical observations
  70. GRB 000630: Detection of the Optical Afterglow
  71. GRB000630, Revised BVRI Field Photometry
  72. GRB000630, Optical Observations
  73. GRB000630, optical observations
  74. GRB000630, optical observations
  75. GRB000630, BVRI Field Photometry
  76. GRB000630, optical observations
  77. GRB000630, optical observations
  78. GRB000630: Optical observations
  79. GRB000630, Radio Observations
  80. possible optical counterpart of GRB 000630
  81. GRB 000623, optical observations
  82. GRB 000620, optical observations
  83. GRB000418, HST/STIS Observations
  84. GRB990123: Late-time HST/STIS observations of the host
  85. GRB 990506, HST/STIS Observations of the Host Galaxy
  86. GRB 000620: J-band observations
  87. GRB000620, optical observations
  88. GRB000615: H-band observations
  89. GRB990308, HST/STIS observations of the host galaxy
  90. GRB000620 - Optical observations
  91. GRB000620 Optical observations
  92. IPN annulus for GRB000620
  93. GRB000620: BeppoSAX WFC and GRBM detection
  94. GRB000615, Radio observations
  95. GRB000607, optical observations
  96. GRB 000615: NIR further observations
  97. GRB990123, HST/STIS observations of the host galaxy
  98. GRB000616 optical observations
  99. GRB 000615, near-infrared observations
  100. GRB 990123: Late-time HST/STIS 50CCD observations of the host

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