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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"

42564 results found.

  1. GRB 990308a and GRB 990308b
  2. GRB990308 (Trig. 7457), optical observations
  3. GRB990308, Possible new SGR~0209+70
  4. GRB981220, IPN localization
  5. GRB 981220, radio observations
  6. GRB 990123, Field Photometry
  7. GRB 990217, radio observations
  8. BATSE Resumes Normal Operations
  9. BATSE Flight Anomaly
  10. GRB990217: BeppoSAX/GRBM data
  11. Optical Observations of GRB990217
  12. GRB990123: Caltech STIS Photometry and Images
  13. GRB990123 observations
  14. GRB990217 Optical observation
  15. GRB990217, WFC position
  16. GRB990123, Optical Observation
  17. GRB 990123: Discovery of the Probable Host Galaxy
  18. GRB 990123: Reduced HST Images
  19. For Immediate Posting to GCN - HST Data GRB 990123 Available
  20. GRB19990123 observations
  21. GRB 990123: Updated Keck Spectroscopy Results
  22. GRB981220, field photometry
  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. GRB990123, Upcoming HST Service Observations
  28. GRB990123, 15-GHz limits
  29. GRB 990123: New Constraints on Possible Foreground Galaxies
  30. GRB990123 Optical Observations
  31. GRB990123, Probability of gravitational lensing
  32. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  33. GRB 990123: Continued Radio Observations
  34. GRB990123, Preliminary Lens Search Results
  35. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  36. On the Lensing Interpretation of GRB 990123
  37. Search for Potential Images of GRB 990123
  38. Search for Potential Images of GRB 990123
  39. GRB990123, Optical BVRI Observations
  40. GRB 990123: near-infrared observations.
  41. GRB990123, OSSE observations
  42. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  43. GRB990123: NIR Observation
  44. GRB990123, ASCA X-ray observation of afterglow
  45. "GRB 990123: New BV Observations"
  46. GRB 990123 Optical Follow-Up
  47. GRB 990123: BATSE Observations
  48. GRB 990123 Keck Spectrum update
  49. GRB990123 IPN annulus
  50. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  51. GRB990123 Optical Observations
  52. GRB 990123 Spectroscopic Redshifts
  53. GRB 990123: New Optical Observations, Decay Measure
  54. GRB 990123 Optical Follow-Up
  55. GRB 990123: Possible Gravitationally Lensed Burst?
  56. GRB 990123 optical observations
  57. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  58. GRB 990123 radio observations
  59. GRB 990123, new radio source
  60. GRB990123, Optical observation
  61. GRB 990123: Optical Decay Slope
  62. GRB 990123 r-band photometry
  63. GRB 990123 Optical Follow-up
  64. GRB990123, early optical counterpart detection
  65. GRB990123 Optical Observation
  66. GRB990123, BeppoSAX-NFI X-ray afterglow detection
  67. GRB 990123: Bright New Source, Possible Optical Transient
  68. GRB 990123, Radio observations
  69. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  70. SN 1999E & GRB 980919
  71. Possible identification of SN1999E with GRB980910
  72. Optical Observations of GRB 981220
  73. GRB 981226: radio variable
  74. GRB981220
  75. GRB981220, Correction to GCN 179
  76. GRB981220, Optical Observations
  77. GRB 981220 Optical observations
  78. GRB 981226 Optical Observations
  79. GRB 980613: Spectroscopy of the host galaxy
  80. GRB981226, sub-millimeter observations
  81. GRB981220, sub-millimeter observations
  82. GRB 981220 and GRB 981226, optical observations
  83. GRB981226 Optical Observations
  84. GRB981226 BeppoSAX follow up
  85. GRB 981226
  86. GRB 981226 optical observations
  87. radio observations of GRB 981226
  88. GRB981220 B, R and I band observations
  89. GRB981226, BeppoSAX-NFI follow-up
  90. Optical Observations of GRB981226
  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. GRB 981220, radio observations
  99. GRB 981220: BeppoSAX/GRBM results
  100. GRB981220 I-band Observations

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