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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"

35427 results found.

  1. GRB 990316, Optical observations
  2. GRB990316, Optical observations
  3. GRB 990316 optical observations
  4. GRB990316: simultaneous optical observation
  5. ASM/IPN error box for GRB 990308 (BATSE #7457)
  6. GRB990308 not a new SGR
  7. GRB 990308a and GRB 990308b
  8. GRB990308 (Trig. 7457), optical observations
  9. GRB981220, IPN localization
  10. GRB 981220, radio observations
  11. GRB 990123, Field Photometry
  12. GRB 990217 Optical Observations
  13. GRB 990217, radio observations
  14. Optical Observations of GRB990217
  15. GRB990123: Caltech STIS Photometry and Images
  16. GRB990123 observations
  17. GRB990123, Optical Observation
  18. GRB 990123: Discovery of the Probable Host Galaxy
  19. GRB 990123: Reduced HST Images
  20. For Immediate Posting to GCN - HST Data GRB 990123 Available
  21. GRB19990123 observations
  22. GRB 990123: BVRI standards in the field
  23. GRB 990123: Updated Keck Spectroscopy Results
  24. GRB981220, field photometry
  25. GRB 990123 NOT Spectrum Update
  26. GRB990123, Optical observation
  27. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  28. GRB 990123: Publicly available reduced HST images
  29. GRB990123, Upcoming HST Service Observations
  30. GRB 990123: New Constraints on Possible Foreground Galaxies
  31. GRB990123 Optical Observations
  32. GRB990123, Probability of gravitational lensing
  33. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  34. GRB 990123: Continued Radio Observations
  35. GRB990123, Preliminary Lens Search Results
  36. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  37. On the Lensing Interpretation of GRB 990123
  38. Search for Potential Images of GRB 990123
  39. Search for Potential Images of GRB 990123
  40. GRB990123, Optical BVRI Observations
  41. GRB 990123: near-infrared observations.
  42. GRB990123, OSSE observations
  43. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  44. "GRB 990123: New BV Observations"
  45. GRB 990123 Optical Follow-Up
  46. GRB 990123; Addendum to GCN 223
  47. GRB 990123: BATSE Observations
  48. GRB 990123 Keck Spectrum update
  49. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  50. GRB990123 Optical Observations
  51. GRB 990123 Spectroscopic Redshifts
  52. GRB 990123: New Optical Observations, Decay Measure
  53. GRB 990123 Optical Follow-Up
  54. GRB 990123: Possible Gravitationally Lensed Burst?
  55. GRB 990123 optical observations
  56. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  57. GRB 990123 radio observations
  58. GRB 990123, new radio source
  59. GRB990123, Optical observation
  60. GRB 990123: Optical Decay Slope
  61. GRB 990123 r-band photometry
  62. GRB 990123 Optical Follow-up
  63. GRB990123, early optical counterpart detection
  64. GRB990123 Optical Observation
  65. GRB 990123: Bright New Source, Possible Optical Transient
  66. GRB 990123, Radio observations
  67. SN 1999E & GRB 980919
  68. Possible identification of SN1999E with GRB980910
  69. Optical Observations of GRB 981220
  70. GRB 981226: radio variable
  71. GRB981220
  72. GRB981220, Optical Observations
  73. GRB 981220 Optical observations
  74. GRB 981226 Optical Observations
  75. GRB 980613: Spectroscopy of the host galaxy
  76. GRB981226, sub-millimeter observations
  77. GRB981220, sub-millimeter observations
  78. GRB 981220 and GRB 981226, optical observations
  79. GRB 981226 radio observations
  80. GRB 981226
  81. GRB 981226 optical observations
  82. radio observations of GRB 981226
  83. GRB981220 B, R and I band observations
  84. GRB 981220:Optical Observations
  85. GRB 981220 optical R and I observations
  86. GRB981226, BeppoSAX Christmas GRB
  87. GRB 981226 - Infrared Observations
  88. GRB 981226 optical observations
  89. GRB 981220
  90. GRB 981220, radio observations
  91. GRB981226 Optical Observation
  92. GRB 981220, radio observations
  93. GRB 981220: BeppoSAX/GRBM results
  94. GRB981220 I-band Observations
  95. GRB 981220
  96. GRB 981220 Optical Observations
  97. GRB 981220, optical observations
  98. GRB 980326/Host Galaxy
  99. GRB981220 IPN error box
  100. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results

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