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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"

42240 results found.

  1. GRB 000926, Optical Observations
  2. GRB000926 - Optical observations
  3. GRB000911: optical VLT observations
  4. GRB000926 K'-band Observation
  5. GRB000926 : increasing optical decay slope
  6. GRB000926 optical observations
  7. GRB000926 - Optical observations
  8. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  9. J and K band observations of GRB 000926
  10. GRB000911 Optical Observations
  11. GRB 000926: Lightcurve Update and Predictions
  12. GRB 000926, optical observation by Oksanen (vsnet-grb)
  13. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  14. GRB000926: Optical observations
  15. CONCAM crude optical limits before and after GRB000926
  16. GRB 000926: Preliminary R-band Lightcurve
  17. GRB 000926 HST/Chandra TOO Status
  18. Spectroscopic Redshift of GRB 000926
  19. GRB 000926, Optical Observation
  20. GRB000926, radio observations
  21. GRB 000926: Optical candidate
  22. Optical candidate for GRB000926
  23. IPN triangulation of GRB000926
  24. GRB 000911, BVRI field photometry
  25. GRB000911: Corrected coordinates
  26. GRB000911: Sub-millimeter observations
  27. GRB000911: Optical Transient
  28. GRB000911, Radio and Optical observations
  29. GRB000911, Radio observations
  30. GRB000911: Optical observations
  31. False GRB alarm from RXTE/ASM on 8 Sept 2000
  32. GRB 000830: Optical observations
  33. GRB000830: Optical observations
  34. GRB000830, TNG B-band observations
  35. GRB000830, BVRI field photometry
  36. GRB000830: Optical observations
  37. GRB000210, Optical observations
  38. Chandra Position of GRB000210
  39. "Snapshot" afterglow IDs and GRB 000830
  40. GRB000830: Optical observations
  41. IPN triangulation of GRB000830
  42. HST/STIS observations of the host galaxy of GRB 980329
  43. HST/STIS observations of the chaotic environment of GRB 980613
  44. SGR 1806-20 burst activity
  45. GRB000812, TNG R-band observations
  46. GRB000801 & GRB000730, Gamma Ray Observations
  47. GRB000812, Radio observations
  48. GRB000801, VLT-Antu R-band observations
  49. GRB000301C, UBVI optical observations
  50. GRB 991208 Host Galaxy Imaging
  51. IPN localization of GRB000730B
  52. GRB 990510: Possible detection of a host galaxy
  53. GRB 990510 Host Galaxy Discovery
  54. GRB 000727, optical observations
  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. GRB000620, Radio Observations
  59. GRB981226, HST/STIS observations of the host galaxy
  60. GRB000630, optical observations
  61. GRB 000630: Detection of the Optical Afterglow
  62. GRB000630, Revised BVRI Field Photometry
  63. GRB000630, Optical Observations
  64. GRB000630, optical observations
  65. GRB000630, optical observations
  66. GRB000630, BVRI Field Photometry
  67. GRB000630, optical observations
  68. GRB000630, optical observations
  69. GRB000630: Optical observations
  70. GRB000630, Radio Observations
  71. possible optical counterpart of GRB 000630
  72. GRB 000623, optical observations
  73. GRB 000620, optical observations
  74. GRB000418, HST/STIS Observations
  75. GRB 990506, HST/STIS Observations of the Host Galaxy
  76. GRB000623
  77. GRB000620, optical observations
  78. GRB000615: H-band observations
  79. GRB990308, HST/STIS observations of the host galaxy
  80. GRB000620 - Optical observations
  81. GRB000620 Optical observations
  82. IPN annulus for GRB000620
  83. GRB000620: BeppoSAX WFC and GRBM detection
  84. GRB000615, Radio observations
  85. GRB000607, optical observations
  86. GRB 000615: NIR further observations
  87. GRB990123, HST/STIS observations of the host galaxy
  88. GRB000616 optical observations
  89. GRB 000615, near-infrared observations
  90. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  91. GRB000616 [IPN Position]
  92. GRB000615B [IPN Position]
  93. GRB000615, further R-band photometry
  94. GRB 000615: NIR observations
  95. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  96. GRB000615, R-band photometry
  97. GRB980425, HST/STIS observations of the host galaxy
  98. GRB000615: BeppoSAX GRB Alert
  99. The Hosts of GRB 980703 and GRB 971214
  100. GRB 000301C: Further Late-Time HST/STIS observations

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