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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"

32505 results found.

  1. GRB 990506, armchair astronomy
  2. GRB 990506, optical observations from +1 to +3 hours
  3. GRB 990506, optical observations
  4. GRB990506 observation plan
  5. New IPN/RXTE error box for GRB990506
  6. IPN localization for GRB990506
  7. GRB 970228: Redshift and properties of the host galaxy
  8. GRB981220 VLBA observations
  9. GRB990321 REFINED IPN ANNULUS
  10. GRB990323 PRECISE IPN POSITION
  11. GRB 990316 Optical Observations
  12. GRB 990316, Radio observations
  13. GRB 990316, Optical observations
  14. GRB990316, Optical observations
  15. GRB 990316 optical observations
  16. GRB990316: simultaneous optical observation
  17. GRB990308 not a new SGR
  18. GRB 990308a and GRB 990308b
  19. GRB990308 (Trig. 7457), optical observations
  20. GRB981220, IPN localization
  21. GRB 981220, radio observations
  22. GRB 990123, Field Photometry
  23. GRB 990217, radio observations
  24. BATSE Resumes Normal Operations
  25. BATSE Flight Anomaly
  26. GRB990123: Caltech STIS Photometry and Images
  27. GRB990123 observations
  28. GRB990123, Optical Observation
  29. GRB 990123: Discovery of the Probable Host Galaxy
  30. GRB 990123: Reduced HST Images
  31. For Immediate Posting to GCN - HST Data GRB 990123 Available
  32. GRB19990123 observations
  33. GRB 990123: Updated Keck Spectroscopy Results
  34. GRB 990123 NOT Spectrum Update
  35. GRB990123, Optical observation
  36. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  37. GRB 990123: Publicly available reduced HST images
  38. GRB 990123: New Constraints on Possible Foreground Galaxies
  39. GRB990123 Optical Observations
  40. GRB990123, Probability of gravitational lensing
  41. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  42. GRB 990123: Continued Radio Observations
  43. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  44. On the Lensing Interpretation of GRB 990123
  45. Search for Potential Images of GRB 990123
  46. Search for Potential Images of GRB 990123
  47. GRB990123, Optical BVRI Observations
  48. GRB 990123: near-infrared observations.
  49. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  50. GRB990123: NIR Observation
  51. "GRB 990123: New BV Observations"
  52. GRB 990123 Optical Follow-Up
  53. GRB 990123; Addendum to GCN 223
  54. GRB 990123: BATSE Observations
  55. GRB 990123 Keck Spectrum update
  56. GRB990123 IPN annulus
  57. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  58. GRB990123 Optical Observations
  59. GRB 990123 Spectroscopic Redshifts
  60. GRB 990123: New Optical Observations, Decay Measure
  61. GRB 990123 Optical Follow-Up
  62. GRB 990123: Possible Gravitationally Lensed Burst?
  63. GRB990123, optical observation
  64. GRB 990123 optical observations
  65. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  66. GRB 990123 radio observations
  67. GRB 990123, new radio source
  68. GRB990123, Optical observation
  69. GRB 990123: Optical Decay Slope
  70. GRB 990123 r-band photometry
  71. GRB 990123 Optical Follow-up
  72. GRB990123, early optical counterpart detection
  73. GRB990123 Optical Observation
  74. GRB 990123: Bright New Source, Possible Optical Transient
  75. GRB 990123, Radio observations
  76. SN 1999E & GRB 980919
  77. Optical Observations of GRB 981220
  78. GRB 981226: radio variable
  79. GRB981220
  80. GRB981220, Correction to GCN 179
  81. GRB981220, Optical Observations
  82. GRB 981220 Optical observations
  83. GRB 981226 Optical Observations
  84. GRB 980613: Spectroscopy of the host galaxy
  85. GRB981226, sub-millimeter observations
  86. GRB981220, sub-millimeter observations
  87. GRB 981220 and GRB 981226, optical observations
  88. GRB981226 Optical Observations
  89. GRB 981226 radio observations
  90. GRB 981226
  91. radio observations of GRB 981226
  92. GRB981220 B, R and I band observations
  93. Optical Observations of GRB981226
  94. GRB 981220:Optical Observations
  95. GRB 981220 optical R and I observations
  96. GRB981226, BeppoSAX Christmas GRB
  97. GRB 981226 - Infrared Observations
  98. GRB 981220
  99. GRB 981220, radio observations
  100. GRB 981220, radio observations

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