document: debris disk systems provide a look at an intermediate stage of stellar system evolution . 
   they represent the transition between the early formation of stars and planets in a primordial protoplanetary disk as seen toward pre - main sequence stars , and the mature stage of an evolved system , like our solar system , which is clear of all primordial material and retains only a hint of secondary products ( e.g. , zodiacal dust ) , the final remnants of the stellar and planetary formation process . 
   although a debris disk has lost most of its primordial material , the observed infrared luminosity of circumstellar dust , caused by collisions of planetismals and other small bodies , is typically several orders of magnitude larger than estimated for the kuiper and asteroid belts in our solar system @xcite . 
   ever since the detection of dusty circumstellar material around main sequence stars via infrared excesses @xcite , researchers have been looking for circumstellar gas phase absorption @xcite . of the initial major infrared excess main sequence stars , 
   only @xmath0 pic showed gas phase absorption in optical absorption lines ( e.g. , and ) , due to its disk morphology and edge - on orientation @xcite . 
   such on orientation provides a unique opportunity to simultaneously measure both the dust and gas components of a debris disk , at an interesting transition near the end of stellar and planetary formation . 
   only a few other edge - on debris disks have been found since , including @xmath0 car @xcite , hd85905 @xcite , hr10 @xcite , and au mic ( @xcite @xcite ; @xcite @xcite ) . @xcite 
   observed @xmath0 car , hd85905 , hr10 with the _ 
   spitzer space telescope _ and did not find strong infrared excesses toward any of them , although an optical monitoring campaign showed clear signs of gas variability , as noted by researchers earlier . 
   however , the magnitude of circumstellar absorption in these systems is lower than observed toward @xmath0 pic . 
   long monitoring campaigns of @xmath0  pic ( e.g. , * ? ? ? 
   * ) , find significant short - term absorption variability . 
   this variability can be explained by gas clouds very close to the star , which are caused by evaporating , star - grazing , km - sized objects , simply referred to as , falling evaporating bodies ( feb s ; * ? ? ? 
   . a strong `` stable '' component , at rest in the stellar reference frame , is also detected toward @xmath0  pic ( e.g. , * ? ? ? 
   the distribution of gas in this component , contrary to the variable component located very close to the star , is dispersed throughout the extended dust disk @xcite . 
   a `` stable '' absorption component in a gas phase resonance line can be caused by either intervening circumstellar or interstellar gas . 
   measuring the interstellar medium ( ism ) along the line of sight and in the locality surrounding a circumstellar disk candidate , is critical to characterizing any `` contaminating '' ism absorption @xcite . in particular 
   , the sun resides in a large scale ism structure known as the local bubble , whose boundary at @xmath4100pc is defined by a significant quantity of interstellar material @xcite . 
   if a `` stable '' absorption component is observed at the stellar radial velocity , and similar absorption is not detected toward any proximate stars , it is likely that the absorption component is caused by circumstellar material .    using near - infrared scattered light observations taken with the _ hubble space telescope _ , @xcite discovered that the debris disk surrounding hd32297 has an edge - on orientation . 
   disk emission extends out to @xmath4400au in their observations , while radii @xmath633.6au are occulted by the coronagraphic obstacle . 
   optical scattered light observations by @xcite confirmed this orientation and extended the range of disk emission to @xmath41680au 
   . the edge - on orientation of hd32297 makes it an ideal target for gas phase absorption measurements . 
   observations of the d doublet ( 5895.9242 and 5889.9510 ) toward hd32297 were made over several epochs . 
   the doublet is among the strongest transitions in the optical wavelength band , appropriate for observing interstellar @xcite and circumstellar @xcite absorption toward nearby stars . 
   in addition , several stars in close angular proximity to hd32297 were observed , in order to reconstruct the ism absorption profile along the line of sight . 
   stellar parameters of the observed targets are given in table  [ tab : basics ] , and the observational parameters are listed in table  [ tab : fits ] . 
   high resolution optical spectra were obtained using the coud spectrometer on the 2.7 m harlan j. smith telescope at mcdonald observatory . 
   the spectra were obtained at a resolution of @xmath7240,000 , using the 2dcoud spectrograph @xcite in the cs21 configuration . 
   the data were reduced using image reduction and analysis facility ( iraf ; * ? ? ? * ) and interactive data language ( idl ) routines to subtract the bias , flat field the images , remove scattered light and cosmic ray contamination , extract the echelle orders , calibrate the wavelength solution , and convert to heliocentric velocities . 
   wavelength calibration images were taken using a th - ar hollow cathode before and after each target . 
   numerous weak water vapor lines are commonly present in spectra around the doublet , and must be modeled and removed , in order to measure an accurate interstellar ( or circumstellar ) absorption profile . 
   i use a forward modeling technique demonstrated by @xcite to remove telluric line contamination in the vicinity of the d lines , with a terrestrial atmosphere model ( at - atmospheric transmission program , from airhead software , boulder , co ) developed by erich grossman . with two absorption lines , it is straightforward to identify contaminating telluric absorption . 
   all absorption lines were fit using standard methods ( e.g. ,  2.2 in * ? ? ? * ) . 
   gaussian absorption components are fit to both d lines simultaneously using atomic data from @xcite , and then convolved with the instrumental line spread function . fitting the lines 
   simultaneously reduces the influence of systematic errors , such as continuum placement and contamination by weak telluric features . 
   the free parameters are the central velocity ( @xmath8 ) , the line width or doppler parameter ( @xmath9 ) , and the column density ( @xmath10 ) of ions along the line of sight . 
   the fits are shown in figure  [ fig : hd32297_figna1 ] and fit parameters with 1@xmath11 statistical errors are listed in table  [ tab : fits ] . 
   in addition , the spectra were used to estimate the stellar radial velocity ( @xmath12 ) and projected stellar rotation ( @xmath13 ) for hd32297 , bd+07 777s , and bd+07 778 ( see table  [ tab : basics ] ) , quantities not listed in simbad for these targets . 
   the radial velocities of all 3 objects differ significantly , and therefore it is unlikely that they are physically associated . 
   note that the radial velocity of hd32297 ( @xmath14 km  s@xmath15 ) is measured from broad and h@xmath16 stellar absorption lines , and therefore is not tightly constrained . 
   the left column of figure  [ fig : hd32297_figna1 ] shows that absorption is clearly detected toward hd32297 in 5 observations over 5 months . 
   two components are easily distinguished , a strong component at @xmath424.5 km  s@xmath15 and a weaker component at @xmath420.5 km  s@xmath15 . 
   the spectral region for 5 stars in close angular proximity to hd32297 is also shown in figure  [ fig : hd32297_figna1 ] . only a single ism component , at @xmath424.2 km  s@xmath15 , is detected in the 3 distant neighbors , indicating that large scale interstellar material is located at a distance between 59.4112pc . 
   all targets located beyond this material , including hd32297 , should have a similar ism absorption feature . 
   this strong ism absorption is probably associated with the boundary material of the local bubble , which is estimated to be @xmath490 pc in this direction @xcite . 
   if located at this distance , the physical separation of the interstellar material observed toward hd32297 and the material toward bd+07 777s ( @xmath17 0@xmath19 ) is 0.025pc , bd+07 778 ( 2@xmath14 ) is 0.064pc , and 18 ori ( 5@xmath181 ) is 8.1pc . toward hd32297 
   s two closest neighbors , the ism absorption is almost identical in projected velocity and column density to the strong absorption seen toward hd32297 , while toward 18 ori , the absorption differs slightly in both @xmath8 and @xmath10 , indicating that any small scale morphological variations in the local bubble shell are on scales @xmath20.1pc but @xmath68pc . 
   small scale variations in the local bubble shell have been detected by @xcite on scales @xmath40.5pc . 
   it is unlikely that the unique 20.5 km  s@xmath15 feature observed toward hd32297 is caused by a small scale interstellar structure . although small ism structures ( 0.012.0pc ) have been observed ( e.g. , * ? ? ? 
   * ; * ? ? ? 
   * ) , it is more likely that the unique feature is due to absorption in the circumstellar environment surrounding hd32297 because ( 1 ) hd32297 is known to be an edge - on debris disk , ( 2 ) no similar absorption is detected in the very close neighboring sightlines ( 0.030.08pc ) , and ( 3 ) the absorption matches the stellar radial velocity . 
   temporal variability is also a hallmark of circumstellar material ( e.g. , @xcite , @xcite , @xcite ) . to search for variability , figure  [ fig : hd32297_diff ] 
   shows difference spectra of all observations . 
   some indication of temporal variability on time scales of months is detected . 
   for example , between the 2005 sep and 2006 feb observations , the @xmath420.5 km  s@xmath15 feature became stronger and the separation between the circumstellar and interstellar features became less distinct , despite the fact that the 2006 feb observations were made at a slightly higher resolving power . 
   the redshifted variability seen between 2005 sep and 2006 feb is @xmath45@xmath11 above the standard deviation . 
   the same pattern is seen in both lines , indicating that the telluric contamination is not causing the variation . 
   slight changes in the resolving power of our instrument could mimic this variable behavior , differentially moving light from the cores of the line to the wings ( or vice versa ) . 
   however , resolution variability should cause ( 1 ) symmetric features in the wings of the line whereas we see a feature only to the blue of the ism feature and not to the red , and ( 2 ) should have a stronger effect on stronger absorption features , whereas the feature is roughly identical in both lines , which could be caused if the absorbing material covers only a fraction of the stellar disk , as has been seen toward @xmath0 pic @xcite . 
   this data alone provides only a subtle indication of temporal variation in , partially because any significant absorption toward the red , is masked by the strong ism feature . 
   redshifted circumstellar absorption dominates the gas absorption variability toward @xmath0 pic ( e.g. , * ? ? ? 
   * ) , while no temporal variability has ever been detected in toward @xmath0 pic , only the `` stable '' absorption component is seen in this ion @xcite . 
   circumstellar variability in has been detected in other edge - on debris disks , e.g. , @xmath0 car , hd85905 , and hr10 @xcite . any redshifted absorption occuring in this object could cause fluctuations in the measured column density of the `` constant '' ism feature . 
   little evidence for variability is found toward the blue . 
   these observations indicate that hd32297 has the strongest circumstellar disk signature detected around a nearby main sequence debris disk star . 
   even compared to @xmath0 pic , the prototypical edge - on debris disk with absorption column densities of @xmath19@xmath20 @xcite , the gas disk around hd32297 , with @xmath3 , has 5@xmath21 the column density . 
   a crude estimate of the gas mass surrounding hd32297 can be made if it is assumed to have the same morphology and abundances as the stable gas around @xmath0 pic . although the observations of hd32297 indicate some red - shifted temporal variability , much of the gas is stable over all observations . 
   using @xmath0 pic as a proxy , the variable gas is likely located very close to the star @xcite , while the stable gas at rest in the stellar frame , likely traces the bulk dust disk @xcite . for this calculation , 
   i assume all the gas is in the stable component , and therefore this gas mass estimate should be considered an upper limit . 
   the morphology of the disk is assumed to follow a broken power law density profile , as fit to the emission profile of the @xmath0 pic disk ( see equation  1 of @xcite ) , and assumed to extend out to the edge of the debris disk at @xmath41680au @xcite . 
   the abundances in the hd32297 disk are assumed to be similar to @xmath0 pic @xcite , where the ratio @xmath22@xmath23@xmath24 , is based on @xmath0 pic measurements by @xcite and limits by @xcite . given these assumption , i calculate a gas mass , distributed through the bulk debris disk surrounding hd32297 at @xmath25 . 
   future observations are planned to continue monitoring the temporal variability of the circumstellar gas toward hd32297 to determine the ratio of stable to variable gas , and measure the gas disk absorption , in order to independently measure the to ratio . 
   a more definitive detection of temporal variability may require monitoring excited lines which will show circumstellar absorption , but not the strong interstellar feature . 
   i present the first high resolution optical spectra of the doublet toward the debris disk hd32297 and stars in close angular proximity . 
   a summary of results include :    \(1 ) two absorption components are detected toward hd32297 , while only one is detected toward its proximate neighbors located at a comparable distance . 
   the extra absorption component in the spectrum of hd32297 , which is also at rest in the stellar reference frame , is therefore likely caused by circumstellar material . 
   + ( 2 ) the ism absorption is similar among hd32297 and its two closest neighbors , and is likely due to absorption from the shell that defines the boundary of the local bubble . 
   some variation in local bubble absorption is detected toward 18 ori . 
   + ( 3 ) radial velocities of hd32297 , bd+07 777s , and bd+07 778 are measured and differ significantly , indicating that they are likely not physically associated . 
   + ( 4 ) some indication of temporal variability is detected over several epochs of observations . 
   instrumental resolution variations and masking by the strong ism absorption , make a definitive detection of circumstellar variability difficult . + ( 5 ) the measured circumstellar feature toward hd32297 ( @xmath26 ) is the strongest such absorption measured toward any nearby main sequence debris disk , @xmath45 times greater than the column density of the prototypical edge - on debris disk , @xmath0 pic . 
   + ( 6 ) if the morphology and abundances of the stable gas component around hd32297 are assumed to be similar to @xmath0 pic , i estimate an upper limit to the gas mass in the circumstellar disk surrounding hd32297 of @xmath40.3 @xmath5 . 
   support for this work was provided by nasa through hubble fellowship grant hst - hf-01190.01 awarded by the space telescope science institute , which is operated by the association of universities for research in astronomy , inc . 
   , for nasa , under contract nas 5 - 26555 . 
   i would like to thank d.  doss , g.  harper , and a.  brown , for their assistance with these observations . 
   the insightful comments by the anonymous referee were very helpful . 
   lllcllcclcc 32297 & bd+07 777 & a0 & 8.13 & @xmath4 + 20 & @xmath480 & 192.83 & 20.17 & 112@xmath27 & 0.0000 & 0.0 + & bd+07 777s & g0 & 10.2 & 55 & @xmath42 & 192.85 & 20.17 & & 0.0156 & 0.030 + 32304 & bd+07 778 & g5 & 6.87 & 1.4 & @xmath43.5 & 192.88 & 20.17 & 134@xmath28 & 0.0406 & 0.079 + 30739 & @xmath29 ori & a1vn & 4.35 & + 24 & 212 & 189.82 & 21.83 & 59.4@xmath30 & 3.2653 & 3.4 + 31295 & @xmath31 ori & a0v & 4.66 & + 13 & 120 & 189.35 & 20.25 & 37.0@xmath32 & 3.2748 & 2.1 + 34203 & 
   18 ori & a0v & 5.52 & 8.2 & 70 & 191.29 & 15.25 & 112.9@xmath33 & 5.1306 & 10.1 +    lllcccccc 32297 & bd+07 777 & 2005 sep 15 & + 28.2 & 1.565 & 31 & 20.459 @xmath34 0.030 & 0.38 @xmath34 0.28 & 10.97@xmath35 + & & & & & & 24.546 @xmath34 0.012 & 0.742 @xmath34 0.063 & 12.388@xmath36 + 32297 & bd+07 777 & 2006 jan 26 & 22.8 & 1.253 & 17 & 20.50 @xmath34 0.27 & 1.23 @xmath34 0.55 & 11.384 @xmath34 0.077 + & & & & & & 24.30 @xmath34 0.12 & 0.84 @xmath34 0.21 & 12.16@xmath37 + 32297 & bd+07 777 & 2006 jan 28 & 23.4 & 1.266 & 22 & 20.48 @xmath34 0.23 & 1.24 @xmath34 0.42 & 11.449@xmath38 + & & & & & & 24.34 @xmath34 0.17 & 0.82 @xmath34 0.31 & 11.98@xmath39 + 32297 & bd+07 777 & 2006 jan 29 & 23.7 & 1.288 & 20 & 20.42 @xmath34 0.20 & 1.71 @xmath34 0.28 & 11.454@xmath40 + & & & & & & 24.424 @xmath34 0.086 & 0.71 @xmath34 0.23 & 12.02@xmath41 + 32297 & bd+07 777 & 2006 feb 15 & 27.5 & 1.199 & 39 & 20.51 @xmath34 0.26 & 1.14 @xmath34 0.41 & 11.297@xmath42 + & & & & & & 24.41 @xmath34 0.13 & 0.94 @xmath34 0.30 & 11.97@xmath43 + & bd+07 777s & 2006 feb 16 & 27.7 & 1.238 & 6 & 25.55 @xmath34 0.28 & 1.581 @xmath34 0.078 & 12.03@xmath44 + 32304 & bd+07 778 & 2006 feb 16 & 27.7 & 1.244 & 52 & 24.583 @xmath34 0.083 & 1.65 @xmath34 0.15 & 12.18@xmath37 + 30739 & @xmath29 ori & 2006 feb 16 & 28.3 & 1.213 & 133 & & & @xmath45 + 31295 & @xmath31 ori & 2004 oct 18 & + 21.1 & 1.761 & 100 & & & @xmath46 + 34203 & 18 ori & 2006 feb 15 & 27.3 & 1.189 & 117 & 22.464 @xmath34 0.022 & 1.150 @xmath34 0.036 & 11.403@xmath47 +
summary: near - infrared and optical imaging of hd32297 indicate that it has an edge - on debris disk , similar to @xmath0 pic . 
   i present high resolution optical spectra of the doublet toward hd32297 and stars in close angular proximity . 
   a circumstellar absorption component is clearly observed toward hd32297 at the stellar radial velocity , which is not observed toward any of its neighbors , including the nearest only 0@xmath19 away . 
   an interstellar component is detected in all stars @xmath290pc , including hd32297 , likely due to the interstellar material at the boundary of the local bubble . 
   radial velocity measurements of the nearest neighbors , bd+07777s and bd+07778 , indicate that they are unlikely to be physically associated with hd32297 . 
   the measured circumstellar column density around hd32997 , @xmath3 , is the strongest absorption measured toward any nearby main sequence debris disk , even the prototypical edge - on debris disk , @xmath0 pic . assuming that the morphology and abundances of the gas component around hd32297 are similar to @xmath0 pic , i estimate an upper limit to the gas mass in the circumstellar disk surrounding hd32297 of @xmath40.3 @xmath5 .