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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"

15247 results found.

  1. GRB 990705, R-band observations
  2. Updated IPN localization of GRB990705
  3. IPN localization of GRB990705
  4. GRB 990704, optical observations
  5. GRB990704
  6. Refined BeppoSAX-WFC position of GRB990704: Errata Corrige
  7. GRB990704, optical observations
  8. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  9. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  10. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  11. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  12. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  13. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  14. radio observations of X-ray/GRB transient field
  15. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  16. Optical report on X-ray/GRB transient
  17. BeppoSAX: A new fast X-ray transient
  18. GRB 990506 R band observations
  19. GRB990510: X-ray afterglow
  20. VLT spectrum of GRB990510
  21. GRB 990510: Broad Band Break
  22. GRB 990510: BeppoSAX/GRBM observations
  23. GRB 990510 optical observations
  24. GRB 990506, optical observations
  25. GRB 990506, Optical Observations
  26. GRB 990506 optical observations
  27. GRB 990506 optical observations
  28. GRB990506 observation plan
  29. New IPN/RXTE error box for GRB990506
  30. GRB 970228: Redshift and properties of the host galaxy
  31. GRB 990316, Radio observations
  32. GRB 990316, Optical observations
  33. GRB 990316 optical observations
  34. GRB990308 not a new SGR
  35. GRB 990308a and GRB 990308b
  36. GRB990308 (Trig. 7457), optical observations
  37. GRB990308, Possible new SGR~0209+70
  38. GRB981220, IPN localization
  39. GRB990217: BeppoSAX/GRBM data
  40. GRB990123 observations
  41. GRB 990123: Discovery of the Probable Host Galaxy
  42. GRB 990123: Reduced HST Images
  43. GRB 990123 NOT Spectrum Update
  44. GRB990123, Optical observation
  45. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  46. GRB 990123: New Constraints on Possible Foreground Galaxies
  47. GRB990123 Optical Observations
  48. GRB990123, Probability of gravitational lensing
  49. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  50. GRB 990123: Continued Radio Observations
  51. GRB990123, Preliminary Lens Search Results
  52. On the Lensing Interpretation of GRB 990123
  53. GRB990123, Optical BVRI Observations
  54. GRB990123, OSSE observations
  55. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  56. GRB 990123; Addendum to GCN 223
  57. GRB 990123 Keck Spectrum update
  58. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  59. GRB990123 Optical Observations
  60. GRB 990123 Spectroscopic Redshifts
  61. GRB 990123: New Optical Observations, Decay Measure
  62. GRB 990123: Possible Gravitationally Lensed Burst?
  63. GRB 990123: Optical Decay Slope
  64. GRB 990123 r-band photometry
  65. GRB 990123 Optical Follow-up
  66. GRB990123, early optical counterpart detection
  67. GRB 990123: Bright New Source, Possible Optical Transient
  68. Optical Observations of GRB 981220
  69. GRB981220
  70. GRB 981220 Optical observations
  71. GRB 981226 Optical Observations
  72. GRB 980613: Spectroscopy of the host galaxy
  73. GRB 981220 and GRB 981226, optical observations
  74. GRB 981226
  75. GRB 981226 optical observations
  76. GRB981220 B, R and I band observations
  77. Optical Observations of GRB981226
  78. GRB 981226 - Infrared Observations
  79. GRB 981220
  80. GRB 981220, radio observations
  81. GRB 981220: BeppoSAX/GRBM results
  82. GRB981220 I-band Observations
  83. GRB 981220
  84. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  85. BeppoSAX NFI Observation of GRB980425
  86. GRB 980923 BATSE Observations
  87. SGR1900+14, BeppoSAX-GRBM observations
  88. GRB980703 Very Long Baseline Interferometry
  89. GRB970508 optical observations
  90. GRB980703, Host galaxy multicolor photometry
  91. GRB980703 - BeppoSAX/GRBM detection
  92. GRB980703 optical photometry
  93. GRB980703 optical observations
  94. GRB980703: Radio transient
  95. GRB980703 H-band Observations
  96. GRB980703 Transient Optical Follow-Up
  97. GRB980703: LOTIS observation at early times
  98. GRB 980703: ASM Position & Intensity
  99. SGR1627-41
  100. GRB 980613 Near-IR observations

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