Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
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"
  1. GRB 030324: Radio Observations
  2. GRB030329 observed as a sudden ionospheric disturbance (SID)
  3. IPN triangulation of GRB030426 (annulus)
  4. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  5. IPN triangulation of GRB030425 (single error box)
  6. GRB030329, SPM optical observations (Correction)
  7. GRB030329, SPM optical observations
  8. GRB 030329, the review of the sky area in plate archive (1950-1998)
  9. GRB 030329: Spectral Evolution of SN 2003dh
  10. Optical Observations of GRB 030418 with Magellan
  11. GRB 030329: optical spectropolarimetry at VLT
  12. IPN triangulation of GRB030422C (annulus)
  13. IPN triangulation of GRB030422B (annulus)
  14. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  15. GRB030329: optical polarization
  16. IPN triangulation of GRB030422 (two large error boxes)
  17. GRB 030329 3.5 and 6 cm radio observations at RTF-32 telescope
  18. GRB030329, optical observation
  19. IPN triangulation of GRB030421 (annulus)
  20. MASTER:optical observations GRB030418
  21. MASTER:optical observations probable GRB030414
  22. GRB030329: 444 AAVSO Measurements
  23. IPN triangulation of GRB030419 (annulus)
  24. MASTER:optical observations GRB030416
  25. ROTSE-III prompt optical detections of GRB 030418
  26. GRB030418: Upper limits from recent and historical observations.
  27. GRB030418: Kiso near infrared observations
  28. GRB 030418: Optical afterglow
  29. GRB 030418: Finder for afterglow candidate
  30. GRB 030418: Optical afterglow candidate
  31. GRB 030329 OT position
  32. GRB030329: Optical Observations
  33. OT GRB 030329: early UBVRcIc spectral evolution
  34. GRB030329, UBVRI polarimetry, R-polarization
  35. GRB 030329: SARA Optical Observations
  36. OT GRB 030329: early spectrum
  37. GRB030329: VR Photometry at TNG
  38. GRB030324: Candidate Optical Afterglow (Erratum)
  39. GRB030324: Candidate Optical Afterglow
  40. IPN triangulation of GRB030414 (small error box)
  41. GRB 030413: Optical Observations
  42. GRB 030329 Rc observations
  43. IPN triangulation of GRB030413 (small error box)
  44. IPN triangulation of GRB030410 (annulus)
  45. Superluminal motion in GRB 030329 (Correction)
  46. Superluminal motion in GRB 030329
  47. GRB 030329 and SN 2003dh
  48. GRB030329, optical position
  49. GRB 030329 VLBA Observations
  50. CORRECTION TO IPN TRIANGULATION OF GRB050403
  51. IPN triangulation of GRB030406 (small error box)
  52. IPN triangulation of GRB050403 (small error box)
  53. IPN triangulation of GRB030403 (annulus)
  54. GRB 030329: BVRI photometry at Asiago
  55. GRB 030329, light curve flattens
  56. GRB 030329: VLT V-band photometry
  57. If the SN/GRB connection confirmed
  58. GRB 030329: Supernova Confirmed
  59. GRB030329: RTT150 optical observations
  60. GRB030329: Near Infrared Observations at Gunma
  61. GRB030329: HET spectroscopic monitoring
  62. Kiso observation of the GRB030329 at April 6
  63. GRB 030329, color evolution
  64. GRB030328, UBVRcIc field photometry
  65. GRB030329: Optical observcations
  66. GRB030329: BV photographic observations
  67. GRB 030329 Optical observations
  68. GRB 030329, color evolution
  69. GRB 030329: possible color change
  70. GRB030329: RTT150 optical observations
  71. GRB 030329: Supernova Spectrum Emerging
  72. GRB030329: Kiso B and R band observations
  73. GRB030329: RTT150 optical observation
  74. GRB030329: More AAVSO VR obs
  75. GRB030328: R upper limit after 6 hours by MASTER
  76. GRB 030329: BV photographic observations
  77. GRB 030329: SARA Optical Observations
  78. GRB 030329: SARA Optical Observations
  79. GRB030329, fading resumes
  80. GRB 030329, BVRI photometry
  81. GRB030329: Optical observations
  82. SDSS 0.5m PT observations of GRB030329 (correction)
  83. SDSS 0.5m PT observations of GRB030329
  84. GRB 030329, Optical observations
  85. GRB 030329, nearby galaxies
  86. GRB030329, cessation of fading
  87. GRB030329: final R-band light curve by MASTER
  88. GRB030329 - more 15 GHz radio data
  89. GRB030329 Radio 23/43/90 GHz observations at Nobeyama
  90. GRB 030329: Sub-millimeter detection
  91. GRB 030329: SARA Optical Observations
  92. GRB 030329: SARA Optical Observations
  93. OT GRB light curves and SN predictions
  94. GRB030329, optical observation
  95. GRB030329, optical observation
  96. GRB030329, new UBVRcIc field photometry
  97. GRB 030329, light curve and SN prediction
  98. GRB030329: optical observations at Tokyo Tech
  99. GRB 030329: optical observations
  100. GRB030329: multiple re-brightening phases

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