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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"

37739 results found.

  1. GRB 990506, optical observations from +1 to +3 hours
  2. GRB 990506, optical observations
  3. GRB990506 observation plan
  4. New IPN/RXTE error box for GRB990506
  5. IPN localization for GRB990506
  6. GRB 970228: Redshift and properties of the host galaxy
  7. IPN localization of GRB990427
  8. GRB981220 VLBA observations
  9. GRB990321 REFINED IPN ANNULUS
  10. GRB990323 PRECISE IPN POSITION
  11. GRB990321 IPN TRIANGULATION
  12. GRB 990316 Optical Observations
  13. GRB 990316, Radio observations
  14. GRB 990316, Optical observations
  15. GRB990316, Optical observations
  16. GRB 990316 optical observations
  17. GRB990316: simultaneous optical observation
  18. ASM/IPN error box for GRB 990308 (BATSE #7457)
  19. GRB990308 not a new SGR
  20. GRB 990308a and GRB 990308b
  21. GRB990308 (Trig. 7457), optical observations
  22. GRB981220, IPN localization
  23. GRB 981220, radio observations
  24. GRB 990123, Field Photometry
  25. GRB 990217 Optical Observations
  26. GRB 990217, radio observations
  27. Optical Observations of GRB990217
  28. GRB990123: Caltech STIS Photometry and Images
  29. GRB990123 observations
  30. GRB990123, Optical Observation
  31. GRB 990123: Discovery of the Probable Host Galaxy
  32. GRB 990123: Reduced HST Images
  33. For Immediate Posting to GCN - HST Data GRB 990123 Available
  34. GRB19990123 observations
  35. GRB 990123: BVRI standards in the field
  36. GRB 990123: Updated Keck Spectroscopy Results
  37. GRB981220, field photometry
  38. GRB 990123 NOT Spectrum Update
  39. GRB990123, Optical observation
  40. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  41. GRB 990123: Publicly available reduced HST images
  42. GRB990123, Upcoming HST Service Observations
  43. GRB 990123: New Constraints on Possible Foreground Galaxies
  44. GRB990123 Optical Observations
  45. GRB990123, Probability of gravitational lensing
  46. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  47. GRB 990123: Continued Radio Observations
  48. GRB990123, Preliminary Lens Search Results
  49. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  50. On the Lensing Interpretation of GRB 990123
  51. Search for Potential Images of GRB 990123
  52. Search for Potential Images of GRB 990123
  53. GRB990123, Optical BVRI Observations
  54. GRB 990123: near-infrared observations.
  55. GRB990123, OSSE observations
  56. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  57. "GRB 990123: New BV Observations"
  58. GRB 990123 Optical Follow-Up
  59. GRB 990123; Addendum to GCN 223
  60. GRB 990123: BATSE Observations
  61. GRB 990123 Keck Spectrum update
  62. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  63. GRB990123 Optical Observations
  64. GRB 990123 Spectroscopic Redshifts
  65. GRB 990123: New Optical Observations, Decay Measure
  66. GRB 990123 Optical Follow-Up
  67. GRB 990123: Possible Gravitationally Lensed Burst?
  68. GRB 990123 optical observations
  69. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  70. GRB 990123 radio observations
  71. GRB 990123, new radio source
  72. GRB990123, Optical observation
  73. GRB 990123: Optical Decay Slope
  74. GRB 990123 r-band photometry
  75. GRB 990123 Optical Follow-up
  76. GRB990123, early optical counterpart detection
  77. GRB990123 Optical Observation
  78. GRB 990123: Bright New Source, Possible Optical Transient
  79. GRB 990123, Radio observations
  80. SN 1999E & GRB 980919
  81. Possible identification of SN1999E with GRB980910
  82. Optical Observations of GRB 981220
  83. GRB 981226: radio variable
  84. GRB981220
  85. GRB981220, Optical Observations
  86. GRB 981220 Optical observations
  87. GRB 981226 Optical Observations
  88. GRB 980613: Spectroscopy of the host galaxy
  89. GRB981226, sub-millimeter observations
  90. GRB981220, sub-millimeter observations
  91. GRB 981220 and GRB 981226, optical observations
  92. GRB 981226 radio observations
  93. GRB 981226
  94. GRB 981226 optical observations
  95. radio observations of GRB 981226
  96. GRB981220 B, R and I band observations
  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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