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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"

37934 results found.

  1. GRB 970228: Redshift and properties of the host galaxy
  2. IPN localization of GRB990427
  3. GRB981220 VLBA observations
  4. GRB990321 REFINED IPN ANNULUS
  5. GRB990323 PRECISE IPN POSITION
  6. GRB990321 IPN TRIANGULATION
  7. GRB 990316 Optical Observations
  8. GRB 990316, Radio observations
  9. GRB 990316, Optical observations
  10. GRB990316, Optical observations
  11. GRB 990316 optical observations
  12. GRB990316: simultaneous optical observation
  13. ASM/IPN error box for GRB 990308 (BATSE #7457)
  14. GRB990308 not a new SGR
  15. GRB 990308a and GRB 990308b
  16. GRB990308 (Trig. 7457), optical observations
  17. GRB981220, IPN localization
  18. GRB 981220, radio observations
  19. GRB 990123, Field Photometry
  20. GRB 990217 Optical Observations
  21. GRB 990217, radio observations
  22. Optical Observations of GRB990217
  23. GRB990123: Caltech STIS Photometry and Images
  24. GRB990123 observations
  25. GRB990123, Optical Observation
  26. GRB 990123: Discovery of the Probable Host Galaxy
  27. GRB 990123: Reduced HST Images
  28. For Immediate Posting to GCN - HST Data GRB 990123 Available
  29. GRB19990123 observations
  30. GRB 990123: BVRI standards in the field
  31. GRB 990123: Updated Keck Spectroscopy Results
  32. GRB981220, field photometry
  33. GRB 990123 NOT Spectrum Update
  34. GRB990123, Optical observation
  35. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  36. GRB 990123: Publicly available reduced HST images
  37. GRB990123, Upcoming HST Service Observations
  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. GRB990123, Preliminary Lens Search Results
  44. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  45. On the Lensing Interpretation of GRB 990123
  46. Search for Potential Images of GRB 990123
  47. Search for Potential Images of GRB 990123
  48. GRB990123, Optical BVRI Observations
  49. GRB 990123: near-infrared observations.
  50. GRB990123, OSSE observations
  51. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  52. "GRB 990123: New BV Observations"
  53. GRB 990123 Optical Follow-Up
  54. GRB 990123; Addendum to GCN 223
  55. GRB 990123: BATSE Observations
  56. GRB 990123 Keck Spectrum update
  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. GRB 990123 optical observations
  64. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  65. GRB 990123 radio observations
  66. GRB 990123, new radio source
  67. GRB990123, Optical observation
  68. GRB 990123: Optical Decay Slope
  69. GRB 990123 r-band photometry
  70. GRB 990123 Optical Follow-up
  71. GRB990123, early optical counterpart detection
  72. GRB990123 Optical Observation
  73. GRB 990123: Bright New Source, Possible Optical Transient
  74. GRB 990123, Radio observations
  75. SN 1999E & GRB 980919
  76. Possible identification of SN1999E with GRB980910
  77. Optical Observations of GRB 981220
  78. GRB 981226: radio variable
  79. GRB981220
  80. GRB981220, Optical Observations
  81. GRB 981220 Optical observations
  82. GRB 981226 Optical Observations
  83. GRB 980613: Spectroscopy of the host galaxy
  84. GRB981226, sub-millimeter observations
  85. GRB981220, sub-millimeter observations
  86. GRB 981220 and GRB 981226, optical observations
  87. GRB 981226 radio observations
  88. GRB 981226
  89. GRB 981226 optical observations
  90. radio observations of GRB 981226
  91. GRB981220 B, R and I band observations
  92. GRB 981220:Optical Observations
  93. GRB 981220 optical R and I observations
  94. GRB981226, BeppoSAX Christmas GRB
  95. GRB 981226 - Infrared Observations
  96. GRB 981226 optical observations
  97. GRB 981220
  98. GRB 981220, radio observations
  99. GRB981226 Optical Observation
  100. GRB 981220, radio observations

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