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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"

32494 results found.

  1. GRB 990316, Radio observations
  2. GRB 990316, Optical observations
  3. GRB990316, Optical observations
  4. GRB 990316 optical observations
  5. GRB990316: simultaneous optical observation
  6. GRB990308 not a new SGR
  7. GRB 990308a and GRB 990308b
  8. GRB990308 (Trig. 7457), optical observations
  9. GRB981220, IPN localization
  10. GRB 981220, radio observations
  11. GRB 990123, Field Photometry
  12. GRB 990217, radio observations
  13. BATSE Resumes Normal Operations
  14. BATSE Flight Anomaly
  15. GRB990123: Caltech STIS Photometry and Images
  16. GRB990123 observations
  17. GRB990123, Optical Observation
  18. GRB 990123: Discovery of the Probable Host Galaxy
  19. GRB 990123: Reduced HST Images
  20. For Immediate Posting to GCN - HST Data GRB 990123 Available
  21. GRB19990123 observations
  22. GRB 990123: Updated Keck Spectroscopy Results
  23. GRB 990123 NOT Spectrum Update
  24. GRB990123, Optical observation
  25. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  26. GRB 990123: Publicly available reduced HST images
  27. GRB 990123: New Constraints on Possible Foreground Galaxies
  28. GRB990123 Optical Observations
  29. GRB990123, Probability of gravitational lensing
  30. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  31. GRB 990123: Continued Radio Observations
  32. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  33. On the Lensing Interpretation of GRB 990123
  34. Search for Potential Images of GRB 990123
  35. Search for Potential Images of GRB 990123
  36. GRB990123, Optical BVRI Observations
  37. GRB 990123: near-infrared observations.
  38. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  39. GRB990123: NIR Observation
  40. "GRB 990123: New BV Observations"
  41. GRB 990123 Optical Follow-Up
  42. GRB 990123; Addendum to GCN 223
  43. GRB 990123: BATSE Observations
  44. GRB 990123 Keck Spectrum update
  45. GRB990123 IPN annulus
  46. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  47. GRB990123 Optical Observations
  48. GRB 990123 Spectroscopic Redshifts
  49. GRB 990123: New Optical Observations, Decay Measure
  50. GRB 990123 Optical Follow-Up
  51. GRB 990123: Possible Gravitationally Lensed Burst?
  52. GRB990123, optical observation
  53. GRB 990123 optical observations
  54. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  55. GRB 990123 radio observations
  56. GRB 990123, new radio source
  57. GRB990123, Optical observation
  58. GRB 990123: Optical Decay Slope
  59. GRB 990123 r-band photometry
  60. GRB 990123 Optical Follow-up
  61. GRB990123, early optical counterpart detection
  62. GRB990123 Optical Observation
  63. GRB 990123: Bright New Source, Possible Optical Transient
  64. GRB 990123, Radio observations
  65. SN 1999E & GRB 980919
  66. Optical Observations of GRB 981220
  67. GRB 981226: radio variable
  68. GRB981220
  69. GRB981220, Correction to GCN 179
  70. GRB981220, Optical Observations
  71. GRB 981220 Optical observations
  72. GRB 981226 Optical Observations
  73. GRB 980613: Spectroscopy of the host galaxy
  74. GRB981226, sub-millimeter observations
  75. GRB981220, sub-millimeter observations
  76. GRB 981220 and GRB 981226, optical observations
  77. GRB981226 Optical Observations
  78. GRB 981226 radio observations
  79. GRB 981226
  80. radio observations of GRB 981226
  81. GRB981220 B, R and I band observations
  82. Optical Observations of GRB981226
  83. GRB 981220:Optical Observations
  84. GRB 981220 optical R and I observations
  85. GRB981226, BeppoSAX Christmas GRB
  86. GRB 981226 - Infrared Observations
  87. GRB 981220
  88. GRB 981220, radio observations
  89. GRB 981220, radio observations
  90. GRB 981220: BeppoSAX/GRBM results
  91. GRB981220 I-band Observations
  92. GRB 981220
  93. GRB 981220 Optical Observations
  94. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  95. BeppoSAX NFI Observation of GRB980425
  96. GRB980425 Optical Follow-up
  97. GRB980425: X-ray revised positions
  98. GRB980703 Very Long Baseline Interferometry
  99. GRB970508 optical observations
  100. Optical Observations of the Host Galaxy of GRB 980519

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