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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"

36033 results found.

  1. IPN localization of GRB990427
  2. GRB981220 VLBA observations
  3. GRB990321 REFINED IPN ANNULUS
  4. GRB990323 PRECISE IPN POSITION
  5. GRB990321 IPN TRIANGULATION
  6. GRB 990316 Optical Observations
  7. GRB 990316, Radio observations
  8. GRB 990316, Optical observations
  9. GRB990316, Optical observations
  10. GRB 990316 optical observations
  11. GRB990316: simultaneous optical observation
  12. ASM/IPN error box for GRB 990308 (BATSE #7457)
  13. GRB990308 not a new SGR
  14. GRB 990308a and GRB 990308b
  15. GRB990308 (Trig. 7457), optical observations
  16. GRB981220, IPN localization
  17. GRB 981220, radio observations
  18. GRB 990123, Field Photometry
  19. GRB 990217 Optical Observations
  20. GRB 990217, radio observations
  21. Optical Observations of GRB990217
  22. GRB990123: Caltech STIS Photometry and Images
  23. GRB990123 observations
  24. GRB990123, Optical Observation
  25. GRB 990123: Discovery of the Probable Host Galaxy
  26. GRB 990123: Reduced HST Images
  27. For Immediate Posting to GCN - HST Data GRB 990123 Available
  28. GRB19990123 observations
  29. GRB 990123: BVRI standards in the field
  30. GRB 990123: Updated Keck Spectroscopy Results
  31. GRB981220, field photometry
  32. GRB 990123 NOT Spectrum Update
  33. GRB990123, Optical observation
  34. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  35. GRB 990123: Publicly available reduced HST images
  36. GRB990123, Upcoming HST Service Observations
  37. GRB 990123: New Constraints on Possible Foreground Galaxies
  38. GRB990123 Optical Observations
  39. GRB990123, Probability of gravitational lensing
  40. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  41. GRB 990123: Continued Radio Observations
  42. GRB990123, Preliminary Lens Search Results
  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. GRB990123, OSSE observations
  50. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  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. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  57. GRB990123 Optical Observations
  58. GRB 990123 Spectroscopic Redshifts
  59. GRB 990123: New Optical Observations, Decay Measure
  60. GRB 990123 Optical Follow-Up
  61. GRB 990123: Possible Gravitationally Lensed Burst?
  62. GRB 990123 optical observations
  63. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  64. GRB 990123 radio observations
  65. GRB 990123, new radio source
  66. GRB990123, Optical observation
  67. GRB 990123: Optical Decay Slope
  68. GRB 990123 r-band photometry
  69. GRB 990123 Optical Follow-up
  70. GRB990123, early optical counterpart detection
  71. GRB990123 Optical Observation
  72. GRB 990123: Bright New Source, Possible Optical Transient
  73. GRB 990123, Radio observations
  74. SN 1999E & GRB 980919
  75. Possible identification of SN1999E with GRB980910
  76. Optical Observations of GRB 981220
  77. GRB 981226: radio variable
  78. GRB981220
  79. GRB981220, Optical Observations
  80. GRB 981220 Optical observations
  81. GRB 981226 Optical Observations
  82. GRB 980613: Spectroscopy of the host galaxy
  83. GRB981226, sub-millimeter observations
  84. GRB981220, sub-millimeter observations
  85. GRB 981220 and GRB 981226, optical observations
  86. GRB 981226 radio observations
  87. GRB 981226
  88. GRB 981226 optical observations
  89. radio observations of GRB 981226
  90. GRB981220 B, R and I band observations
  91. GRB 981220:Optical Observations
  92. GRB 981220 optical R and I observations
  93. GRB981226, BeppoSAX Christmas GRB
  94. GRB 981226 - Infrared Observations
  95. GRB 981226 optical observations
  96. GRB 981220
  97. GRB 981220, radio observations
  98. GRB981226 Optical Observation
  99. GRB 981220, radio observations
  100. GRB 981220: BeppoSAX/GRBM results

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