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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

23611 results found.

  1. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  2. LIGO/Virgo/KAGRA S241106ba: 1 counterpart neutrino candidate event from an IceCube neutrino search
  3. LIGO/Virgo/KAGRA S241102o: 1 counterpart neutrino candidate event from an IceCube neutrino search
  4. GRB 241105A: Swift-XRT afterglow detection
  5. GRB 241104A: Swift-XRT observations
  6. GRB 240511A: LCO upper limits
  7. GRB 241104A: Fermi GBM Observation
  8. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  9. GRB 241104A: NOT optical non-detection
  10. GRB 241104A: SVOM/VT optical candidate
  11. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  12. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  13. EP241104a: EP detection of GRB 241104A X-ray emission
  14. GRB 241010A: host galaxy redshift z = 0.977
  15. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  16. GRB 240821A: further radio observations with the VLA
  17. EP241101a: EP-FXT observations update
  18. EP241103a: GIT optical upper limit
  19. EP241021a: OHP/T193 further optical observations
  20. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  21. EP241103a: GOTO optical upper limit
  22. EP241103a: Swift XRT detection and improved X-ray position
  23. EP241021a: continued SOAR observations
  24. EP241101a: Optical upper limits with Kinder observations
  25. EP241101a: OHP/T193 optical observations
  26. EP241103a: Gemini optical limits
  27. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  28. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  29. EP241103A: LCO optical observations
  30. EP241103a: an X-ray transient detected by Einstein Probe
  31. GRB 241030A: Rapid release of TESS data.
  32. S241102cy: Identification of a GW compact binary merger candidate
  33. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  34. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  35. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  36. GRB241030A: OHP/T193 optical observations
  37. GRB 241101A: FRAM-ORM optical limit
  38. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  39. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  40. GRB 241030A: further SAO RAS optical observations
  41. GRB 241030A: Optical Observations via Virtual Telescope Project
  42. EP241021a: Liverpool Telescope optical follow-up observations
  43. GRB 241026A: SAO RAS optical observations
  44. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  45. GRB 241101A: Swift detection of a burst
  46. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  47. EP241021a: OHP/T193 optical observations
  48. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  49. GRB 241030B: Montarrenti Observatory optical upper limit
  50. EP241026b: Liverpool Telescope optical follow-up
  51. GRB 241030A: SAO RAS optical observations
  52. EP241021a: AMI-LA radio detection
  53. GRB 241030B : GIT optical upper limits
  54. GRB 241030B: LCOGT Optical Upper Limits
  55. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  56. GRB 241030B: Swift/UVOT Detection
  57. GRB 241029A: LCO optical detection
  58. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  59. GRB 241030B : MITSuME Akeno optical upper limits
  60. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  61. GRB 241030B: SVOM/VT optical afterglow observations
  62. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  63. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  64. GRB 241030B: BTA observations
  65. GRB 241029A: SVOM/VT optical afterglow observations
  66. GRB 241030B: Enhanced Swift-XRT position
  67. GRB 241030B: optical observations from the INAF Asiago Observatory
  68. GRB241030B: GRANDMA/TAROT Upper Limit
  69. GRB 241030B: SAO RAS optical observations
  70. GRB 241030B: AKO Optical Afterglow Detection
  71. GRB 241030B: Nanshan/HMT optical afterglow detection
  72. GRB 241030B: Swift detection of a burst
  73. GRB 240912A: radio detection with the VLA
  74. GRB 241030A: AKO Optical Afterglow Detection
  75. GRB 241030A: Swift/UVOT Detection
  76. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  77. GRB 241030A: SVOM/C-GFT optical observations
  78. GRB 241026A: LBT optical observations
  79. EP241021a: Optical rebrightening observations with Mephisto
  80. GRB 241030A: Multiband optical detection with Mephisto
  81. GRB 241030A: SVOM/VT optical afterglow observations
  82. GRB 241030A : MITSuME Akeno optical afterglow detection
  83. GRB 241030A: Enhanced Swift-XRT position
  84. GRB 241029A: GROWTH-India Telescope optical follow up
  85. GRB 241030A: Keck/LRIS spectroscopic redshift z = 1.411
  86. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  87. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  88. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  89. GRB 241029A: SAO RAS optical observations
  90. GRB 241026A: SAO RAS optical observations
  91. EP241021a: SAO RAS observations of rebrightening
  92. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  93. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  94. GRB 241026A: Swift/UVOT Upper Limits
  95. GRB 241029A: AKO Optical Afterglow Detection
  96. GRB 241029A: GOTO optical afterglow detection
  97. EP241021a: continued SOAR observations confirm optical rebrightening
  98. GRB 241029A: Xinglong-2.16m optical afterglow confirmation
  99. GRB 241029A: Mephisto observations
  100. EP 241026b: LBT possible optical counterpart (brightening source)

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