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"

17851 results found.

  1. GRB030329: optical polarization
  2. GRB030329, optical observation
  3. MASTER:optical observations GRB030418
  4. MASTER:optical observations probable GRB030414
  5. GRB030418: Upper limits from recent and historical observations.
  6. GRB030418: Kiso near infrared observations
  7. GRB030329: Optical Observations
  8. OT GRB 030329: early spectrum
  9. GRB030329, optical position
  10. Kiso observation of the GRB030329 at April 6
  11. GRB 030329, color evolution
  12. GRB030328, UBVRcIc field photometry
  13. GRB 030329 Optical observations
  14. GRB030329: Kiso B and R band observations
  15. SDSS 0.5m PT observations of GRB030329 (correction)
  16. SDSS 0.5m PT observations of GRB030329
  17. GRB030329: final R-band light curve by MASTER
  18. GRB030329, new UBVRcIc field photometry
  19. GRB 030329 , SPM optical observations
  20. GRB030329: Optical observations at Teramo
  21. GRB 030329: Radio observations at GMRT
  22. GRB 030329: Additional Mt. Laguna Optical Observations
  23. GRB 030329: Observations with ANDICAM
  24. GRB 030329: optical observations
  25. GRB 030324: Optical and NIR Observations
  26. GRB030329: R band light curve by MASTER
  27. GRB030329 - Light curve flattening
  28. GRB 030324, optical search
  29. GRB030329 - near contemporaneous optical limits from CONCAM
  30. GRB 030329, optical observations
  31. GRB030328: X-ray Fading and Spectrum Measured with Chandra
  32. GRB030329, BVRcIc field photometry
  33. GRB030329, SPM optical observations
  34. GRB030329 optical observations
  35. GRB 030329: Optical pre-Imaging
  36. GRB 030329: Upper limit from 5.6 hours before trigger
  37. GRB030328: X-ray Afterglow Observed with Chandra
  38. GRB 030329, R-band observations
  39. GRB030329: Upper limits from recent and historical observations.
  40. GRB 030329: Optical Afterglow Observations
  41. GRB 030329: precise position from Kyoto images
  42. GRB 030328: optical observations
  43. GRB 030329: Optical afterglow fading
  44. GRB 030328: OT photometry
  45. GRB030328: optical photometry at the TNG
  46. GRB 030328: Optical observations
  47. GRB 030328: Finding chart
  48. GRB 030328: Optical afterglow candidate
  49. GRB030324 optical observation
  50. GRB030131, BVRcIc field photometry
  51. Possible GRB030323 localized by INTEGRAL
  52. GRB030323: Detection on 2003/03/24
  53. IPN triangulation of GRB030325 (single small error box)
  54. IPN triangulation of GRB030325 (two small error boxes)
  55. GRB030323: V, R, I photometry
  56. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  57. VLT/FORS2 spectra of GRB 030323
  58. GRB030323, optical observations
  59. GRB030324, BVRcIc field photometry
  60. GRB030323, BVRcIc field calibration
  61. Possible GRB 030320 localized by INTEGRAL
  62. GRB030226, BVRc observations
  63. Chandra detection of the X-ray afterglow of GRB 030226
  64. GRB030227: Kiso optical upper limit
  65. GRB030227, BVRcIc field photometry
  66. GRB030226, BVRcIc field calibration
  67. GRB 030228, optical observations
  68. GRB 030227: Confirmed Optical Afterglow (S1-A)
  69. GRB 030226: Optical observations
  70. GRB 030227: fading of candidate optical afterglow 'S1-A'
  71. GRB030227:Optical observations
  72. GRB 20030226: Upper limits from recent and historical observations
  73. GRB 030227, possible optical counterpart of XMM-Newton source
  74. XMM-Newton observation of GRB030227
  75. GRB030227: Kiso optical observations
  76. GRB 030227: Kyoto optical observation
  77. GRB030227 localized by INTEGRAL
  78. GRB030226: ESI spectroscopy
  79. GRB 030226 simultaneous optical observations
  80. GRB 030226, optical observations
  81. GRB030226: Optical decay index
  82. GRB 030226: Optical afterglow
  83. GRB 030131: marginal optical detection
  84. GRB 030204: Optical Observations
  85. GRB030204 field photometry
  86. GRB020819: Kiso R and I band observations
  87. GRB030131: Candidate Optical Afterglow
  88. GRB 030131, optical observations
  89. GRB 030131: afterglow candidate
  90. GRB 030115, late-time optical observations
  91. GRB 020819: Host galaxy at Radio Position
  92. GRB 030131 optical observations
  93. GRB 030131 optical observations
  94. A long GRB detected by INTEGRAL
  95. GRB 030115, simultaneous observations by BOOTES-1
  96. GRB 030115: IR observations with IRSF/SIRIUS
  97. GRB030115, afterglow candidate
  98. GRB 021211: R-band observations at late-time
  99. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  100. GRB 030115 : Possible IR counterpart

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