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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"

38260 results found.

  1. GRB 990510 optical observations
  2. GRB 990510 optical observations
  3. Galactic extinction towards GRB 990510
  4. GRB 990510 optical observations
  5. IPN localization of GRB990510
  6. GRB 990506 Radio Observations
  7. GRB 990123, optical monitoring
  8. GRB 990506: BATSE Observations
  9. GRB 990506, optical observations
  10. GRB 990510: Final BeppoSAX-WFC Coordinates
  11. GRB 990506, Optical Observations
  12. GRB 990506 optical observations
  13. GRB 990506 optical observations
  14. GRB 990506, optical observations
  15. GRB990506 observation plan
  16. Refined IPN error box for GRB990506
  17. GRB 990506: Limits on the possible optical transient
  18. GRB 990506, armchair astronomy
  19. GRB 990506, optical observations from +1 to +3 hours
  20. GRB 990506, optical observations
  21. GRB990506 observation plan
  22. New IPN/RXTE error box for GRB990506
  23. IPN localization for GRB990506
  24. GRB 970228: Redshift and properties of the host galaxy
  25. IPN localization of GRB990427
  26. GRB981220 VLBA observations
  27. GRB990321 REFINED IPN ANNULUS
  28. GRB990323 PRECISE IPN POSITION
  29. GRB990321 IPN TRIANGULATION
  30. GRB 990316 Optical Observations
  31. GRB 990316, Radio observations
  32. GRB 990316, Optical observations
  33. GRB990316, Optical observations
  34. GRB 990316 optical observations
  35. GRB990316: simultaneous optical observation
  36. ASM/IPN error box for GRB 990308 (BATSE #7457)
  37. GRB990308 not a new SGR
  38. GRB 990308a and GRB 990308b
  39. GRB990308 (Trig. 7457), optical observations
  40. GRB981220, IPN localization
  41. GRB 981220, radio observations
  42. GRB 990123, Field Photometry
  43. GRB 990217 Optical Observations
  44. GRB 990217, radio observations
  45. Optical Observations of GRB990217
  46. GRB990123: Caltech STIS Photometry and Images
  47. GRB990123 observations
  48. GRB990123, Optical Observation
  49. GRB 990123: Discovery of the Probable Host Galaxy
  50. GRB 990123: Reduced HST Images
  51. For Immediate Posting to GCN - HST Data GRB 990123 Available
  52. GRB19990123 observations
  53. GRB 990123: BVRI standards in the field
  54. GRB 990123: Updated Keck Spectroscopy Results
  55. GRB981220, field photometry
  56. GRB 990123 NOT Spectrum Update
  57. GRB990123, Optical observation
  58. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  59. GRB 990123: Publicly available reduced HST images
  60. GRB990123, Upcoming HST Service Observations
  61. GRB 990123: New Constraints on Possible Foreground Galaxies
  62. GRB990123 Optical Observations
  63. GRB990123, Probability of gravitational lensing
  64. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  65. GRB 990123: Continued Radio Observations
  66. GRB990123, Preliminary Lens Search Results
  67. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  68. On the Lensing Interpretation of GRB 990123
  69. Search for Potential Images of GRB 990123
  70. Search for Potential Images of GRB 990123
  71. GRB990123, Optical BVRI Observations
  72. GRB 990123: near-infrared observations.
  73. GRB990123, OSSE observations
  74. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  75. "GRB 990123: New BV Observations"
  76. GRB 990123 Optical Follow-Up
  77. GRB 990123; Addendum to GCN 223
  78. GRB 990123: BATSE Observations
  79. GRB 990123 Keck Spectrum update
  80. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  81. GRB990123 Optical Observations
  82. GRB 990123 Spectroscopic Redshifts
  83. GRB 990123: New Optical Observations, Decay Measure
  84. GRB 990123 Optical Follow-Up
  85. GRB 990123: Possible Gravitationally Lensed Burst?
  86. GRB 990123 optical observations
  87. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  88. GRB 990123 radio observations
  89. GRB 990123, new radio source
  90. GRB990123, Optical observation
  91. GRB 990123: Optical Decay Slope
  92. GRB 990123 r-band photometry
  93. GRB 990123 Optical Follow-up
  94. GRB990123, early optical counterpart detection
  95. GRB990123 Optical Observation
  96. GRB 990123: Bright New Source, Possible Optical Transient
  97. GRB 990123, Radio observations
  98. SN 1999E & GRB 980919
  99. Possible identification of SN1999E with GRB980910
  100. Optical Observations of GRB 981220

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