Discovery of Faint Nebulosity around a Z Camelopardalis–type Cataclysmic Variable in Antlia: Nova Shell or Ancient Planetary Nebula?
We report our discovery of a faint nebula surrounding a previously little-studied 15th mag variable star, ASASSN-19ds, in the Southern Hemisphere constellation Antlia. Spectra verify that the star is a cataclysmic variable (CV). Using new and archival photometry, we confirm that ASASSN-19ds is an ec...
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IOP Publishing
2025-01-01
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| Series: | The Astronomical Journal |
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| Online Access: | https://doi.org/10.3847/1538-3881/ade9a6 |
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| author | Howard E. Bond Dana Patchick Daniel Stern Jonathan Talbot John R. Thorstensen |
| author_facet | Howard E. Bond Dana Patchick Daniel Stern Jonathan Talbot John R. Thorstensen |
| author_sort | Howard E. Bond |
| collection | DOAJ |
| description | We report our discovery of a faint nebula surrounding a previously little-studied 15th mag variable star, ASASSN-19ds, in the Southern Hemisphere constellation Antlia. Spectra verify that the star is a cataclysmic variable (CV). Using new and archival photometry, we confirm that ASASSN-19ds is an eclipsing binary with an orbital period of 0.139 days (3.34 hr). Moreover, its out-of-eclipse brightness shows a “sawtooth” light curve with an amplitude of ∼1 mag and an interval between peaks that varies between about 3 to nearly 5 weeks. Its mean absolute magnitude in the Gaia system is M _G = +6.5. These combined properties lead to a classification of ASASSN-19ds as a Z Camelopardalis–type CV. We obtained deep narrowband images of the nebulosity, using modest-sized telescopes and extremely long exposure times. Our imagery reveals a bipolar morphology, with thin arcs at the ends of the major axis, likely indicating an interaction with the interstellar medium. We consider several scenarios for the origin of the nebula, but from the existing information we are unable to distinguish between it being ejecta from an unobserved classical-nova outburst several centuries ago, or an ancient planetary nebula. Future observations should be able to decide between these possibilities. At the star’s distance of only ∼557 pc, a nova eruption would have been a spectacular naked-eye event. |
| format | Article |
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| institution | Kabale University |
| issn | 1538-3881 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
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| series | The Astronomical Journal |
| spelling | doaj-art-f781d4da27444f1d99fd0bfcbbb6045b2025-08-20T03:31:58ZengIOP PublishingThe Astronomical Journal1538-38812025-01-01170313710.3847/1538-3881/ade9a6Discovery of Faint Nebulosity around a Z Camelopardalis–type Cataclysmic Variable in Antlia: Nova Shell or Ancient Planetary Nebula?Howard E. Bond0https://orcid.org/0000-0003-1377-7145Dana Patchick1https://orcid.org/0000-0002-9018-9606Daniel Stern2https://orcid.org/0009-0005-9964-1602Jonathan Talbot3https://orcid.org/0009-0009-3986-4336John R. Thorstensen4https://orcid.org/0000-0002-4964-4144Department of Astronomy & Astrophysics, Penn State University , University Park, PA 16802, USA ; heb11@psu.edu; Space Telescope Science Institute , 3700 San Martin Dr., Baltimore, MD 21218, USADeep Sky Hunters Consortium , 1942 Butler Ave., Los Angeles, CA 90025, USAMEA Observatory , 16252 Andalucia Ln., Delray Beach, FL 33446, USAStark Bayou Observatory , 1013 Conely Cir., Ocean Springs, MS 39564, USADepartment of Physics & Astronomy, 6127 Wilder Laboratory, Dartmouth College , Hanover, NH 03755, USAWe report our discovery of a faint nebula surrounding a previously little-studied 15th mag variable star, ASASSN-19ds, in the Southern Hemisphere constellation Antlia. Spectra verify that the star is a cataclysmic variable (CV). Using new and archival photometry, we confirm that ASASSN-19ds is an eclipsing binary with an orbital period of 0.139 days (3.34 hr). Moreover, its out-of-eclipse brightness shows a “sawtooth” light curve with an amplitude of ∼1 mag and an interval between peaks that varies between about 3 to nearly 5 weeks. Its mean absolute magnitude in the Gaia system is M _G = +6.5. These combined properties lead to a classification of ASASSN-19ds as a Z Camelopardalis–type CV. We obtained deep narrowband images of the nebulosity, using modest-sized telescopes and extremely long exposure times. Our imagery reveals a bipolar morphology, with thin arcs at the ends of the major axis, likely indicating an interaction with the interstellar medium. We consider several scenarios for the origin of the nebula, but from the existing information we are unable to distinguish between it being ejecta from an unobserved classical-nova outburst several centuries ago, or an ancient planetary nebula. Future observations should be able to decide between these possibilities. At the star’s distance of only ∼557 pc, a nova eruption would have been a spectacular naked-eye event.https://doi.org/10.3847/1538-3881/ade9a6Planetary nebulaePlanetary nebulae nucleiCataclysmic variable starsDwarf novaeZ Camelopardalis starsNova-like variable stars |
| spellingShingle | Howard E. Bond Dana Patchick Daniel Stern Jonathan Talbot John R. Thorstensen Discovery of Faint Nebulosity around a Z Camelopardalis–type Cataclysmic Variable in Antlia: Nova Shell or Ancient Planetary Nebula? The Astronomical Journal Planetary nebulae Planetary nebulae nuclei Cataclysmic variable stars Dwarf novae Z Camelopardalis stars Nova-like variable stars |
| title | Discovery of Faint Nebulosity around a Z Camelopardalis–type Cataclysmic Variable in Antlia: Nova Shell or Ancient Planetary Nebula? |
| title_full | Discovery of Faint Nebulosity around a Z Camelopardalis–type Cataclysmic Variable in Antlia: Nova Shell or Ancient Planetary Nebula? |
| title_fullStr | Discovery of Faint Nebulosity around a Z Camelopardalis–type Cataclysmic Variable in Antlia: Nova Shell or Ancient Planetary Nebula? |
| title_full_unstemmed | Discovery of Faint Nebulosity around a Z Camelopardalis–type Cataclysmic Variable in Antlia: Nova Shell or Ancient Planetary Nebula? |
| title_short | Discovery of Faint Nebulosity around a Z Camelopardalis–type Cataclysmic Variable in Antlia: Nova Shell or Ancient Planetary Nebula? |
| title_sort | discovery of faint nebulosity around a z camelopardalis type cataclysmic variable in antlia nova shell or ancient planetary nebula |
| topic | Planetary nebulae Planetary nebulae nuclei Cataclysmic variable stars Dwarf novae Z Camelopardalis stars Nova-like variable stars |
| url | https://doi.org/10.3847/1538-3881/ade9a6 |
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