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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"

32501 results found.

  1. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)
  2. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  3. GRB000926 - Optical observations
  4. GRB000926 - Optical observations
  5. GRB 000926, Optical Decay
  6. GRB000911: VLT infrared observation
  7. GRB000926 - Optical observations
  8. GRB000926 - Optical observations
  9. GRB 000926: optical observations
  10. GRB 000926, Optical Observations
  11. GRB000926 - Optical observations
  12. GRB000911: optical VLT observations
  13. GRB000926 : increasing optical decay slope
  14. GRB000926 optical observations
  15. GRB000926 - Optical observations
  16. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  17. J and K band observations of GRB 000926
  18. GRB000911 Optical Observations
  19. GRB 000926: Lightcurve Update and Predictions
  20. GRB 000926, optical observation by Oksanen (vsnet-grb)
  21. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  22. GRB000926: Optical observations
  23. GRB 000926: Preliminary R-band Lightcurve
  24. GRB 000926 HST/Chandra TOO Status
  25. Spectroscopic Redshift of GRB 000926
  26. GRB 000926, Optical Observation
  27. GRB000926, radio observations
  28. GRB 000926: Optical candidate
  29. Optical candidate for GRB000926
  30. IPN triangulation of 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: Optical observations
  43. GRB000210, Optical observations
  44. Chandra Position of GRB000210
  45. GRB000830: Optical observations
  46. HST/STIS observations of the host galaxy of GRB 980329
  47. HST/STIS observations of the chaotic environment of GRB 980613
  48. GRB000812, TNG R-band observations
  49. GRB000801 & GRB000730, Gamma Ray Observations
  50. GRB000812, Radio observations
  51. GRB000801, VLT-Antu R-band observations
  52. GRB000301C, UBVI optical observations
  53. GRB000801, Radio Observations
  54. GRB 991208 Host Galaxy Imaging
  55. Updated IPN coordinates for GRB000801
  56. IPN localization of GRB000801
  57. IPN localization of GRB000730B
  58. GRB 990510: Possible detection of a host galaxy
  59. GRB 990510 Host Galaxy Discovery
  60. GRB 000727, optical observations
  61. GRB 990705, HST/STIS observations of the host galaxy
  62. GRB 990712: Late time HST/STIS Observations
  63. GRB 991216, HST/STIS observations
  64. GRB000620, Radio Observations
  65. GRB981226, HST/STIS observations of the host galaxy
  66. GRB000630, optical observations
  67. GRB 000630: Detection of the Optical Afterglow
  68. GRB000630, Revised BVRI Field Photometry
  69. GRB000630, Optical Observations
  70. GRB000630, optical observations
  71. GRB000630, optical observations
  72. GRB000630, optical observations
  73. GRB000630, optical observations
  74. GRB000630: Optical observations
  75. GRB000630, Radio Observations
  76. possible optical counterpart of GRB 000630
  77. GRB 000623, optical observations
  78. GRB 000620, optical observations
  79. GRB000418, HST/STIS Observations
  80. GRB990123: Late-time HST/STIS observations of the host
  81. GRB 990506, HST/STIS Observations of the Host Galaxy
  82. GRB 000620: J-band observations
  83. GRB000620, optical observations
  84. GRB000615: H-band observations
  85. GRB990308, HST/STIS observations of the host galaxy
  86. GRB000620 - Optical observations
  87. GRB000620 Optical observations
  88. IPN annulus for GRB000620
  89. GRB000615, Radio observations
  90. GRB000607, optical observations
  91. GRB 000615: NIR further observations
  92. GRB990123, HST/STIS observations of the host galaxy
  93. GRB000616 optical observations
  94. GRB 000615, near-infrared observations
  95. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  96. GRB000615, further R-band photometry
  97. GRB 000615: NIR observations
  98. GRB000615, R-band photometry
  99. GRB980425, HST/STIS observations of the host galaxy
  100. The Hosts of GRB 980703 and GRB 971214

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