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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"

32508 results found.

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

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