Skip to main content
New! BOOM Notices and Schema v7.0.0. See news and announcements

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"

35260 results found.

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

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov