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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"

35253 results found.

  1. GRB 000926: optical observations
  2. GRB 000926, Optical Observations
  3. GRB000926 K'-band Observation
  4. GRB000926 : increasing optical decay slope
  5. GRB000926 optical observations
  6. GRB000926 - Optical observations
  7. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  8. J and K band observations of GRB 000926
  9. GRB 000926: Lightcurve Update and Predictions
  10. GRB 000926, optical observation by Oksanen (vsnet-grb)
  11. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  12. CONCAM crude optical limits before and after GRB000926
  13. GRB 000926: Preliminary R-band Lightcurve
  14. GRB 000926 HST/Chandra TOO Status
  15. Spectroscopic Redshift of GRB 000926
  16. GRB 000926, Optical Observation
  17. GRB 000926: Optical candidate
  18. Optical candidate for GRB000926
  19. IPN triangulation of GRB000926
  20. GRB 000911, BVRI field photometry
  21. GRB000911: Sub-millimeter observations
  22. IPN triangulation of GRB000925
  23. IPN triangulation of GRB000911
  24. IPN triangulation of GRB000910
  25. False GRB alarm from RXTE/ASM on 8 Sept 2000
  26. GRB 000830: Optical observations
  27. GRB000830: Optical observations
  28. GRB000830, TNG B-band observations
  29. GRB000830, BVRI field photometry
  30. GRB000830: Optical observations
  31. GRB000210, Optical observations
  32. Chandra Position of GRB000210
  33. "Snapshot" afterglow IDs and GRB 000830
  34. IPN triangulation of GRB000830
  35. HST/STIS observations of the host galaxy of GRB 980329
  36. HST/STIS observations of the chaotic environment of GRB 980613
  37. IPN localization of GRB000820
  38. GRB000801 & GRB000730, Gamma Ray Observations
  39. GRB000730, Gamma Ray Observations
  40. GRB000812, Radio observations
  41. IPN localization of GRB000812
  42. IPN localization of GRB000811
  43. GRB000801, Gamma Ray Observations
  44. GRB000801, VLT-Antu R-band observations
  45. GRB 991208 Host Galaxy Imaging
  46. Updated IPN coordinates for GRB000801
  47. IPN localization of GRB000801
  48. IPN localization of GRB000730B
  49. IPN localization of GRB000730B
  50. IPN localization of GRB000730
  51. GRB 990510: Possible detection of a host galaxy
  52. GRB 990510 Host Galaxy Discovery
  53. GRB 000727, optical observations
  54. IPN localization of GRB000727
  55. GRB 990705, HST/STIS observations of the host galaxy
  56. GRB 990712: Late time HST/STIS Observations
  57. GRB 991216, HST/STIS observations
  58. GRB981226, HST/STIS observations of the host galaxy
  59. GRB 000630: Detection of the Optical Afterglow
  60. GRB000630, Revised BVRI Field Photometry
  61. GRB000630, Optical Observations
  62. GRB000630, optical observations
  63. GRB000630, BVRI Field Photometry
  64. GRB000630, optical observations
  65. GRB000630: Optical observations
  66. possible optical counterpart of GRB 000630
  67. IPN triangulation of GRB000630
  68. GRB 000623, optical observations
  69. GRB 000620, optical observations
  70. GRB000418, HST/STIS Observations
  71. GRB990123: Late-time HST/STIS observations of the host
  72. GRB 990506, HST/STIS Observations of the Host Galaxy
  73. GRB000623
  74. GRB 000620: J-band observations
  75. GRB990308, HST/STIS observations of the host galaxy
  76. IPN annulus for GRB000620
  77. GRB000615, Radio observations
  78. GRB000607, optical observations
  79. GRB 000615: NIR further observations
  80. BeppoSAX ALERT: GRB000620
  81. GRB000620: BeppoSAX Alert
  82. GRB990123, HST/STIS observations of the host galaxy
  83. GRB 000615, near-infrared observations
  84. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  85. GRB000616 [IPN Position]
  86. GRB000615B [IPN Position]
  87. GRB000615, further R-band photometry
  88. GRB 000615: NIR observations
  89. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  90. GRB000615, R-band photometry
  91. GRB980425, HST/STIS observations of the host galaxy
  92. GRB000615: BeppoSAX GRB Alert
  93. The Hosts of GRB 980703 and GRB 971214
  94. GRB 000301C: Further Late-Time HST/STIS observations
  95. GRB000528: follow-up X-ray measurements and update of IPN annulus
  96. GRB980519, HST/STIS observations of the host galaxy
  97. GRB000607, Radio Observations
  98. GRB000604 - Optical observations
  99. GRB000607, A SHORT, HARD BURST
  100. GRB000604, optical observations

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