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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"

35958 results found.

  1. Public availability of BeppoSAX data of GRB000926
  2. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  3. GRB 000926, Optical Decay
  4. GRB000926 - Optical observations
  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. GRB000926 - Optical observations
  12. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  13. J and K band observations of GRB 000926
  14. GRB 000926: Lightcurve Update and Predictions
  15. GRB 000926, optical observation by Oksanen (vsnet-grb)
  16. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  17. CONCAM crude optical limits before and after GRB000926
  18. GRB 000926: Preliminary R-band Lightcurve
  19. GRB 000926 HST/Chandra TOO Status
  20. Spectroscopic Redshift of GRB 000926
  21. GRB 000926, Optical Observation
  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. IPN triangulation of GRB000911
  29. IPN triangulation of GRB000910
  30. False GRB alarm from RXTE/ASM on 8 Sept 2000
  31. GRB 000830: Optical observations
  32. GRB000830: Optical observations
  33. GRB000830, TNG B-band observations
  34. GRB000830, BVRI field photometry
  35. GRB000830: Optical observations
  36. GRB000210, Optical observations
  37. Chandra Position of GRB000210
  38. "Snapshot" afterglow IDs and GRB 000830
  39. IPN triangulation of GRB000830
  40. HST/STIS observations of the host galaxy of GRB 980329
  41. HST/STIS observations of the chaotic environment of GRB 980613
  42. IPN localization of GRB000820
  43. GRB000801 & GRB000730, Gamma Ray Observations
  44. GRB000730, Gamma Ray Observations
  45. GRB000812, Radio observations
  46. IPN localization of GRB000812
  47. IPN localization of GRB000811
  48. GRB000801, Gamma Ray Observations
  49. GRB000801, VLT-Antu R-band observations
  50. GRB 991208 Host Galaxy Imaging
  51. Updated IPN coordinates for GRB000801
  52. IPN localization of GRB000801
  53. IPN localization of GRB000730B
  54. IPN localization of GRB000730B
  55. IPN localization of GRB000730
  56. GRB 990510: Possible detection of a host galaxy
  57. GRB 990510 Host Galaxy Discovery
  58. GRB 000727, optical observations
  59. IPN localization of GRB000727
  60. GRB 990705, HST/STIS observations of the host galaxy
  61. GRB 990712: Late time HST/STIS Observations
  62. GRB 991216, HST/STIS observations
  63. GRB981226, HST/STIS observations of the host galaxy
  64. GRB 000630: Detection of the Optical Afterglow
  65. GRB000630, Revised BVRI Field Photometry
  66. GRB000630, Optical Observations
  67. GRB000630, optical observations
  68. GRB000630, BVRI Field Photometry
  69. GRB000630, optical observations
  70. GRB000630: Optical observations
  71. possible optical counterpart of GRB 000630
  72. IPN triangulation of GRB000630
  73. GRB 000623, optical observations
  74. GRB 000620, optical observations
  75. GRB000418, HST/STIS Observations
  76. GRB990123: Late-time HST/STIS observations of the host
  77. GRB 990506, HST/STIS Observations of the Host Galaxy
  78. GRB000623
  79. GRB 000620: J-band observations
  80. GRB990308, HST/STIS observations of the host galaxy
  81. IPN annulus for GRB000620
  82. GRB000615, Radio observations
  83. GRB000607, optical observations
  84. GRB 000615: NIR further observations
  85. BeppoSAX ALERT: GRB000620
  86. GRB000620: BeppoSAX Alert
  87. GRB990123, HST/STIS observations of the host galaxy
  88. GRB 000615, near-infrared observations
  89. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  90. GRB000616 [IPN Position]
  91. GRB000615B [IPN Position]
  92. GRB000615, further R-band photometry
  93. GRB 000615: NIR observations
  94. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  95. GRB000615, R-band photometry
  96. GRB980425, HST/STIS observations of the host galaxy
  97. GRB000615: BeppoSAX GRB Alert
  98. The Hosts of GRB 980703 and GRB 971214
  99. GRB 000301C: Further Late-Time HST/STIS observations
  100. GRB000528: follow-up X-ray measurements and update of IPN annulus

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